Electric lubricant dispenser, and method for dispensing lubricant from an electric lubricant dispenser.

Abstract

This invention provides a technology that can properly detect the presence of gas in the pump of an electric lubricant dispenser. [Solution] One aspect of the present disclosure provides an electric lubricant dispenser comprising a motor, a pump, a drive circuit, and a control circuit. The pump is driven by the motor and discharges lubricant. The drive circuit drives the motor. The control circuit controls the drive circuit to rotate the motor. While the motor is being driven, the control circuit performs predetermined processing based on whether the load torque meets the requirement that gas is mixed into the pump.

Description

[Technical Field]

[0001] This disclosure relates to an electric lubricant dispenser. [Background technology]

[0002] Patent Document 1 discloses a grease dispensing device equipped with a pump. In this grease dispensing device, the pump receives grease from a tank and dispenses the grease. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-134818 [Overview of the project] [Problems that the invention aims to solve]

[0004] In grease dispensing systems, air can enter the grease inside the pump. If air enters the pump, it can hinder the proper dispensing of grease. For example, the amount of grease dispensed may temporarily decrease or even stop being dispensed altogether.

[0005] One aspect of this disclosure is to provide a technology that can appropriately detect the presence of gas inside a pump. [Means for solving the problem]

[0006] In this disclosure, terms such as “first,” “second,” etc., are intended merely to distinguish elements from one another and not to limit the order or number of elements. Therefore, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element. In addition, the first element may be present without the second element, and similarly, the second element may be present without the first element.

[0007] One aspect of this disclosure is the provision of an electric lubricant dispenser comprising a motor, a pump, a drive circuit, and a control circuit. The pump is driven by a motor. The pump dispenses lubricant. The drive circuit drives the motor.

[0008] The control circuit controls the drive circuit to rotate the motor. The control circuit performs predetermined processing based on whether the load torque satisfies a first requirement while the motor is running. The load torque is the torque generated by the load from the pump, which is part of the torque applied to the motor from the outside. The first requirement indicates that the load torque is present in the pump. The first requirement may also indicate that there is a possibility that gas is present in the pump. That is, the fact that the load torque satisfies the first requirement may mean that there is (or is likely to be) gas present in the pump.

[0009] An electric lubricant dispenser configured in this way can properly detect if gas is mixed into the pump. Another aspect of this disclosure is a method for dispensing lubricant from an electric lubricant dispenser, The pump of the electric lubricant dispenser, configured to dispense lubricant, It is driven by a motor, During motor operation, the load torque, which is the torque generated by the load from the pump among the torque applied to the motor from the outside, satisfies the requirement that gas is mixed into the pump, and based on this, a predetermined process is performed in the electric lubricant dispenser. This provides a method for providing this.

[0010] This method allows for the proper detection of gas contamination in the pump of an electric lubricant dispenser. [Brief explanation of the drawing]

[0011] [Figure 1]Perspective view of the electric lubricant feeder of the first embodiment. [Figure 2] Central longitudinal sectional view of the electric lubricant feeder. [Figure 3] Explanatory diagram for explaining the mechanism in which the plunger moves up and down by the rotation of the motor. [Figure 4] Plan view of the operation panel in the electric lubricant feeder. [Figure 5] Circuit diagram showing the electrical configuration of the electric lubricant feeder. [Figure 6] Functional block diagram of the control circuit in the electric lubricant feeder. [Figure 7] Explanatory diagram showing an example of the operation of the motor when the motor is started in an air-biting state. [Figure 8] Explanatory diagram showing an example of the operation of the motor when the motor decelerates in a normal state. [Figure 9] Explanatory diagram for schematically explaining the torque applied to the motor. [Figure 10] Explanatory diagram showing an example of the operation of the motor (especially the estimated torque) when the motor is started in an air-biting state. [Figure 11] Explanatory diagram showing an example of the operation of the motor (especially the estimated torque) when the motor decelerates in a normal state. [Figure 12] Explanatory diagram showing an example of setting the first threshold value. [Figure 13] Flowchart of the main process. [Figure 14] Flowchart of the process during stop. [Figure 15] Flowchart of the process during operation. [Figure 16] Flowchart of the air-biting detection process of the first embodiment. [Figure 17] Flowchart of the continuation determination process. [Figure 18] Flowchart of the air-biting detection process of the second embodiment. [Figure 19] Explanatory diagram showing an example of the operation of the motor (especially the differential value of the estimated torque) when the motor is started in an air-biting state. [Figure 20] This is an explanatory diagram showing an example of motor operation (particularly the derivative of the estimated torque) when the motor decelerates under normal conditions. [Figure 21] This is a flowchart of the air-entry detection process in the third embodiment. [Figure 22] This is a flowchart of a part of the air-entry detection process in the fourth embodiment. [Figure 23] This is a flowchart of another part of the air entrapment detection process in the fourth embodiment (continuation of Figure 22). [Modes for carrying out the invention]

[0012] [1. Summary of Embodiments] One embodiment may provide an electric lubricant dispenser comprising at least one of the following: Feature 1: Motor. Feature 2: Pump. Feature 3: The pump is configured to be driven by a motor. Feature 4: The pump is configured to dispense lubricant. Feature 5: Drive circuit. Feature 6: The drive circuit is configured to drive the motor. Feature 7: Control circuit. Feature 8: The control circuit is configured to control the drive circuit to rotate the motor (in other words, to perform the first action). Feature 9: The control circuit is configured to perform predetermined processing (in other words, execute a second operation) based on whether the load torque satisfies the first requirement while the motor is running. Feature 10: Load torque is the torque applied to the motor from outside the motor (more specifically, to the rotating shaft) that is generated by the load received from the pump (hereinafter referred to as "pump load") (in other words, the torque caused by the operation of the pump). Feature 11: The first requirement is that the pump contains gas (or bubbles).

[0013] An electric lubricant dispenser possessing at least features 1 to 11 can properly detect the presence of gas in the pump. The motor is in the form of an electric motor. The motor may be configured to generate a driving force (or rotational driving force, or driving torque as described below). The pump may be configured to receive the driving force of the motor directly or indirectly and to be driven by that driving force. "Driven by a motor" may mean receiving and being driven by a driving force (or rotational driving force, or at least a portion of the driving torque) from the motor.

[0014] The motor may be configured to (i) rotate in response to an electric current and (ii) output a drive torque corresponding to the current. The motor may receive an electric current from a drive circuit.

[0015] Examples of motors include DC motors, AC motors, and stepping motors. Examples of DC motors include brushless motors (or brushless DC motors) and brushed DC motors.

[0016] Examples of lubricants include liquid lubricants and semi-solid lubricants. Examples of liquid lubricants include lubricating oils. Examples of semi-solid lubricants include greases. That is, an example of an electric lubricant dispenser includes an electric grease gun.

[0017] The pump may be configured to receive a lubricant and discharge the received lubricant. The lubricant may be introduced into the pump (i.e., received) by pressure applied to the pump outside the pump. Alternatively, the pump may be configured to generate negative pressure within the pump and use that negative pressure to receive (i.e., draw in) the lubricant.

[0018] Pumps can include any form of pump. Examples of pumps include positive displacement pumps. Examples of positive displacement pumps include reciprocating pumps and rotary pumps. Examples of reciprocating pumps include plunger pumps configured with a plunger that reciprocates, and diaphragm pumps configured with a diaphragm that reciprocates. Examples of pumps may also include non-positive displacement pumps.

[0019] The drive circuit may include multiple switching elements connected to the motor. Examples of drive circuits include full-bridge and half-bridge circuits. A full-bridge circuit may be connected to a three-phase motor. A three-phase motor has (i) three terminals configured to receive power, and (ii) is configured to rotate by the power received. The aforementioned brushless motor is a three-phase motor.

[0020] A full-bridge circuit may have six switching elements. Examples of the six switching elements include semiconductor switches and mechanical relays. Examples of semiconductor switches include field-effect transistors (FETs), bipolar transistors, insulated-gate bipolar transistors (IGBTs), thyristors, and solid-state relays (SSRs).

[0021] The six switching elements may include three high-side switches and three low-side switches. The three high-side switches are electrically connected to the positive terminal of the power supply and to the three terminals of the motor, respectively. The three low-side switches are electrically connected to the negative terminal of the power supply and to the three terminals of the motor, respectively. The three high-side switches may be arranged to conduct or interrupt the three positive-side current paths, respectively. The three positive-side current paths electrically connect the three terminals of the motor to the positive terminal of the power supply, respectively. The three low-side switches may be arranged to conduct or interrupt the three negative-side current paths, respectively. The three negative-side current paths electrically connect the three terminals of the motor to the negative terminal of the power supply, respectively.

[0022] In a pump, the pump load can increase, particularly when the lubricant is discharged, due to the pressure from the lubricant. Therefore, the pump load can fluctuate depending on the pump's operation. Specifically, the pump load may increase when the lubricant is discharged and decrease when the lubricant is received. Thus, the pump load can fluctuate periodically. The magnitude of the pump load fluctuation differs depending on whether or not gas is mixed into the pump. When gas is mixed into the pump, the pressure the pump receives from the lubricant is smaller compared to when gas is not mixed in. Therefore, when gas is mixed into the pump, the increase in the pump load when the lubricant is discharged is also suppressed, and this reduces the fluctuation in the pump load.

[0023] The load torque fluctuates in accordance with the changes in the pump load as described above. Both the load torque during lubricant discharge and the range of fluctuation in the load torque are smaller when gas is present in the pump than when no gas is present. Therefore, it is possible to determine whether or not gas is present in the pump based on the load torque.

[0024] The torque applied to the motor from outside the motor (hereinafter referred to as "external input torque") may include load torque and torque other than load torque (hereinafter referred to as "unloaded torque"). Unloaded torque may include (i) mechanical loss torque (e.g., friction) applied to the motor due to mechanical factors or mechanical losses (e.g., friction) occurring in the transmission mechanism described later, and / or (ii) inertial torque applied to the motor due to the motor's moment of inertia. The moment of inertia is due to the mechanical characteristics of the entire transmission system from the motor to the pump through which the driving torque is transmitted.

[0025] The external input torque may be equal to the drive torque, or may be considered to be equal to the drive torque. Load torque can be rephrased as the torque of the driving torque that contributes to the operation of the pump (i.e., the torque used or consumed in the operation of the pump). The torque contributing to the operation of the pump includes at least the torque contributing to the discharge of the lubricant. If the mechanical losses in the pump are small or negligible, the load torque can be considered equal to the torque contributing to the discharge of the lubricant. In other words, if the pump load can be considered to arise solely from the discharge of the lubricant, the load torque can be considered equal to the torque contributing to the discharge of the lubricant. Note that the torque contributing to the operation of the pump may also include at least the torque contributing to the acceptance and discharge of the lubricant. However, the torque contributing to the acceptance of the lubricant is generally smaller than the torque contributing to the discharge and can be ignored.

[0026] The driving torque is the torque that contributes to the operation of the pump (i.e., the torque corresponding to the load torque) and This may include torque that does not contribute to the operation of the pump (i.e., torque corresponding to the unloaded torque). The driving torque may be equal to, or be considered to be equal to, the sum of the loaded torque and the unloaded torque. Specifically, the driving torque may be equal to, or be considered to be equal to, the sum of the loaded torque and at least one of the mechanical loss torque and the inertial torque.

[0027] The control circuit can determine whether the load torque satisfies the first requirement without relying on the current supplied to the motor (in other words, without using the magnitude of the current). The load torque may be obtained by any method. The load torque may be calculated (i.e., estimated) by, for example, a predetermined calculation described later. Alternatively, for example, the electric lubricant dispenser may be equipped with a sensor capable of detecting the magnitude of the pressure applied to the pump when the lubricant is discharged. In this case, the load torque may be obtained based on the magnitude of the pressure detected by the sensor.

[0028] The first requirement may indicate that there is a possibility of gas contamination in the pump. That is, the load torque satisfying the first requirement may mean that there is gas contamination in the pump, or there is a possibility that there is gas contamination in the pump. Alternatively, the statement "there is gas contamination in the pump" may itself encompass the meaning of "there is a possibility that there is gas contamination in the pump."

[0029] The presence of gas in a pump may include (i) gas being present in the lubricant inside the pump, (ii) gas being present in the discharge that is about to be discharged by the pump, and / or (iii) gas being present in the container (e.g., the chamber described below) in which the lubricant is contained within the pump.

[0030] The prescribed procedure may be any procedure that corresponds to the presence of gas in the pump. The prescribed procedure may also be a procedure that should be performed or is preferable to be performed when gas is present in the pump. When gas is present in the pump, the lubricant may not be discharged properly. Specifically, the amount of lubricant discharged may decrease or the lubricant may not be discharged at all. Therefore, the prescribed procedure may be a procedure that corresponds to a state in which the lubricant may not be discharged properly, that is, a procedure that should be performed or is preferable to be performed in that state. Examples of the prescribed procedure are described later.

[0031] In one embodiment, the control circuit may be integrated into a single electronic unit, a single electronic device, or a single circuit board. In one embodiment, the control circuit may be a combination of two or more electronic circuits, two or more electronic units, or two or more electronic devices, each individually provided on or within the electric lubricant dispenser.

[0032] In one embodiment, the control circuit may comprise a microcomputer (or microcontroller or microprocessor), wired logic, application-specific integrated circuits (ASICs), application-specific general-purpose products (ASSPs), programmable logic devices (PLDs) (such as field-programmable gate arrays (FPGAs)), discrete electronic components, and / or a combination thereof.

[0033] In one embodiment, the electric lubricant dispenser may be handheld (in other words, portable). That is, the electric lubricant dispenser may have a grip configured to be held by the user of the electric lubricant dispenser. The electric lubricant dispenser may be used while the grip is held by the user.

[0034] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 11: Feature 12: The first requirement includes that the maximum value of the load torque within a predetermined driving period is less than or equal to a first threshold.

[0035] An electric lubricant dispenser possessing at least features 1 to 12 can accurately detect the presence of gas in the pump. The above feature 12 may also be rephrased as the first requirement being satisfied in accordance with the fact that the maximum value of the load torque within a predetermined driving period is less than or equal to the first threshold.

[0036] The predetermined drive period is a predetermined period of time while the motor is running. If the pump is configured to repeat a predetermined operation, the predetermined drive period may include at least the period during which that predetermined operation is performed.

[0037] The first threshold may be determined to be smaller than the range of load torque that can occur under normal conditions (e.g., its minimum value) and larger than the range of load torque that can occur under abnormal conditions (e.g., its maximum value). Normal conditions correspond to a state where no gas is present in the pump, and abnormal conditions correspond to a state where gas is present in the pump.

[0038] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 12: Feature 13: The first requirement includes that the maximum value of the amplitude of the load torque within a predetermined driving period is less than or equal to the second threshold.

[0039] An electric lubricant dispenser possessing at least features 1-11,13 can accurately detect the presence of gas in the pump. The above feature 13 may be rephrased as the first requirement being satisfied in accordance with the fact that the maximum value of the amplitude within a predetermined drive period is less than or equal to the second threshold. The first requirement may be rephrased as the fact that the amplitude of the load torque does not exceed the second threshold over the predetermined drive period. The amplitude of the load torque may be defined as the difference between the maximum and minimum values ​​of the load torque that changes over time. The maximum value of the amplitude is the difference between the maximum and minimum values ​​of the load torque within a predetermined drive period.

[0040] The second threshold may be determined to be a value smaller than the range of amplitudes that can occur under normal conditions (e.g., its minimum value) and larger than the range of amplitudes that can occur under abnormal conditions (e.g., its maximum value).

[0041] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 13: Feature 14: The first requirement includes the fact that the maximum value of the derivative of the load torque within a predetermined driving period is less than or equal to the third threshold.

[0042] An electric lubricant dispenser possessing at least features 1-11,14 can accurately detect the presence of gas in the pump. The above feature 14 may be rephrased as the first requirement being satisfied in accordance with the fact that the maximum value of the derivative within a predetermined driving period is less than or equal to the third threshold. The first requirement may be rephrased as the derivative not exceeding the third threshold throughout the predetermined driving period.

[0043] The derivative of the load torque may be calculated in any way. For example, the derivative of the load torque may be calculated based on the time derivative, that is, the change in load torque per given unit time. However, it may also be calculated as a differential value. For example, the differential value of the load torque may be calculated based on the rotational angle derivative. That is, the amount of change in the load torque while the motor rotates by a predetermined unit rotational angle may be calculated as the differential value.

[0044] The third threshold may be determined to be a value smaller than the range of absolute values ​​of differentials that can occur under normal conditions (e.g., its minimum value) and larger than the range of absolute values ​​of differentials that can occur under abnormal conditions (e.g., its maximum value).

[0045] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 14: Feature 15: The control circuit is configured to change the first threshold value according to the operating state of the electric lubricant dispenser.

[0046] Electric lubricant dispensers possessing at least features 1-12 and 15 can more accurately detect the presence of gas in the pump. The operating state can include any state that affects the load torque. In other words, the operating state can include any state in which the load torque may change in response to a change in that operating state.

[0047] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 15: Feature 16: The control circuit is configured to change the second threshold value according to the operating state of the electric lubricant dispenser.

[0048] An electric lubricant dispenser possessing at least features 1-11, 13, and 16 can more accurately detect the presence of gas in the pump. One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 16: Feature 17: The control circuit is configured to change the third threshold value according to the operating state of the electric lubricant dispenser.

[0049] Electric lubricant dispensers possessing at least features 1-11, 14, and 17 can more accurately detect the presence of gas in the pump. One embodiment may include, in addition to or instead of, at least one of the features 1 to 17 described above, at least one of the following: Feature 18: The control circuit is configured to set a target rotational speed. The target rotational speed is the target value for the motor's rotational speed. Feature 19: The control circuit is configured to control the drive circuit so that the motor's rotational speed matches the target rotational speed (i.e., the set target rotational speed). Feature 20: The aforementioned operating state includes the target rotational speed.

[0050] An electric lubricant dispenser having at least features 1-12, 15, 18-20, an electric lubricant dispenser having at least features 1-11, 13, 16, 18-20, and an electric lubricant dispenser having at least features 1-11, 14, 17-20 can more accurately detect the presence of gas in the pump.

[0051] One embodiment may include, in addition to or instead of, at least one of the features 1 to 20 described above, at least one of the following: Feature 21: The control circuit is configured to control the drive circuit by outputting a pulse-width modulated signal with a duty cycle to the drive circuit. Feature 22: The drive circuit receives a pulse width modulated signal and operates according to the received pulse width modulated signal. It is configured to drive the motor. Feature 23: The aforementioned operating state includes the duty cycle.

[0052] An electric lubricant dispenser having at least features 1-12, 15, 21-23, an electric lubricant dispenser having at least features 1-11, 13, 16, 21-23, and an electric lubricant dispenser having at least features 1-11, 14, 17, 21-23 can more accurately detect the presence of gas in the pump.

[0053] The drive circuit may be configured to drive the motor by supplying power (or current) to the motor in accordance with the duty cycle. Specifically, the drive circuit may be configured to increase the power (or current) as the duty cycle increases. The duty cycle may increase as the target rotational speed increases.

[0054] If the drive circuit includes the aforementioned plurality of switch elements, at least one of the plurality of switch elements may be configured to (i) receive a pulse width modulated signal and (ii) turn on or off (and thereby conduct or interrupt the corresponding current path) according to its duty cycle. That is, the larger the duty cycle, the longer the period during which it is turned on (i.e., the corresponding current path is conducted), and as a result the power supplied to the motor (and thus the motor output and / or actual rotational speed) may increase.

[0055] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 23: Feature 24: The aforementioned operating state includes the actual rotational speed of the motor (i.e., actual rotational speed).

[0056] An electric lubricant dispenser having at least features 1-12, 15, and 24, an electric lubricant dispenser having at least features 1-11, 13, 16, and 24, and an electric lubricant dispenser having at least features 1-11, 14, 17, and 24 can more accurately detect the presence of gas in the pump.

[0057] The control circuit may set the thresholds to be set (i.e., the first threshold, the second threshold, and / or the third threshold) in any way according to the operating state. The control circuit may set the thresholds according to a pre-prepared function that takes the operating state as a variable. The control circuit may set the thresholds by referring to a pre-prepared table or similar database that associates the operating state with the thresholds.

[0058] The control circuit may increase the first threshold and / or the second threshold and / or the third threshold as the target rotational speed increases. Similarly, the control circuit may increase the first threshold and / or the second threshold and / or the third threshold as the duty cycle increases.

[0059] One embodiment may include, in addition to or instead of, at least one of the features 1 to 24 described above, at least one of the following: Feature 25: The control circuit is configured to obtain the temperature of the electric lubricant dispenser. Feature 26: The operating state includes the temperature.

[0060] An electric lubricant dispenser having at least features 1-12, 15, 25, and 26, an electric lubricant dispenser having at least features 1-11, 13, 16, 25, and 26, and an electric lubricant dispenser having at least features 1-11, 14, 17, 25, and 26 can more accurately detect the presence of gas in the pump.

[0061] The control circuit may acquire the temperature of any (where) the electric lubricant dispenser. The temperature may be the temperature of the lubricant, or a temperature that can be considered to be the temperature of the lubricant (or a change in the lubricant).

[0062] In one embodiment, the electric lubricant dispenser may include a temperature sensor configured and positioned to directly or indirectly detect the temperature of the lubricant. The control circuit may vary a first threshold, a second threshold, and / or a third threshold depending on the temperature detected by the temperature sensor. The temperature sensor may be positioned in direct contact with the lubricant, in which case it can directly detect the temperature of the lubricant. Alternatively, the temperature sensor may be positioned at a distance from the lubricant. The temperature sensor may be in any form capable of detecting temperature. Examples of temperature sensors include positive temperature coefficient (PTC) thermistors, negative temperature coefficient (NTC) thermistors, and critical temperature resistor (CTR) thermistors.

[0063] If one embodiment includes features 12, 25, and 26, the control circuit may be configured to decrease a first threshold as the acquired temperature increases. If one embodiment includes features 13, 25, and 26, the control circuit may be configured to decrease a second threshold as the acquired temperature increases.

[0064] If one embodiment includes features 14, 25, and 26, the control circuit may be configured to decrease the third threshold as the acquired temperature increases. The aforementioned operating conditions may include more than the target rotational speed, duty cycle, actual rotational speed, and temperature described above. Examples of the aforementioned operating conditions include the magnitude of the voltage applied from the drive circuit to the motor, or physical quantities that indirectly indicate the magnitude of that voltage. If the drive circuit is configured to apply the voltage of a power source (e.g., a battery) to the motor, the operating conditions may include the battery voltage. In this case, as the battery voltage decreases, the voltage applied to the motor also decreases. Therefore, the first threshold may be set such that the first threshold decreases as the battery voltage decreases. The same applies to the second and third thresholds. One embodiment may include a voltage detector configured to detect the battery voltage. The voltage detector may be configured to (i) receive the battery voltage and (ii) output a voltage detection signal to a control circuit corresponding to the magnitude of that voltage. The control circuit may (i) obtain the magnitude of the battery voltage based on the voltage detection signal from the voltage detector and (ii) set a first threshold (or a second or third threshold) based on the obtained magnitude.

[0065] One embodiment may include, in addition to or instead of, at least one of the features 1 to 26 described above, at least one of the following: Feature 27: A transmission mechanism connected to the motor and configured to transmit the motor's rotation to the pump. Feature 28: The drive circuit is configured to supply current to the motor and rotate it. Feature 29: The control circuit is configured to calculate the load torque or load-inclusive torque based on the magnitude of the current supplied from the drive circuit to the motor and the acceleration of the motor. The load-inclusive torque is a portion of the torque applied to the motor from the outside, including the load torque and fluctuating in approximately the same manner as the load torque. Feature 30: The control circuit is configured to perform predetermined processing based on whether the calculated load torque, or the load torque included in the calculated load-inclusive torque, satisfies the first requirement.

[0066] In an electric lubricant dispenser that possesses at least features 1-11, 27-30, it is easy to determine whether the load torque meets the first requirement. In one embodiment, the control circuit calculates the load torque based on the following equation (1), or lower The system may be configured to calculate the load-inclusive torque based on formula (2).

[0067]

number

[0068] In the above formula (1) and / or formula (2), The motor current value is the value of the current supplied from the drive circuit to the motor. The motor torque coefficient is the torque coefficient of the motor. The moment of inertia is the moment of inertia of the motor. Motor acceleration is the acceleration of the motor (more specifically, the acceleration of the rotational speed of the rotating shaft). Mechanical torque loss corresponds to the torque that is consumed (in other words, used or lost) by the transmission mechanism from the torque output by the motor.

[0069] The motor torque coefficient can be defined as the torque generated by a motor when a unit current flows through it. The motor torque coefficient is also commonly called the torque constant. It is well known that the torque generated by a motor is expressed as the product of the motor current value and the motor torque coefficient.

[0070] Load-included torque corresponds to the load torque with a constant or approximately constant torque (in other words, bias) added to it. Therefore, fluctuations in load-included torque correspond to fluctuations in load torque (i.e., they coincide or approximately coincide). In other words, evaluating fluctuations in load-included torque is essentially synonymous with evaluating fluctuations in load torque. If the mechanical loss torque is constant or approximately constant, the load-included torque may include the mechanical loss torque.

[0071] The control circuit may determine whether the load torque satisfies the first requirement based on the calculated load-included torque. If the load-included torque includes mechanical loss torque, a predetermined process may be performed based on the fact that the load-included torque satisfies a predetermined requirement corresponding to the first requirement. The load-included torque satisfying the predetermined requirement is equivalent to the load torque included in the load-included torque satisfying the first requirement.

[0072] One embodiment may include, in addition to or instead of, at least one of the features 1 to 30 described above, at least one of the following: Feature 31: The electric lubricant dispenser is equipped with an alert unit. Feature 32: The notification unit is configured to notify information indicating that gas is mixed into the pump. Feature 33: The predetermined process includes broadcasting the information via the notification unit.

[0073] In electric lubricant dispensers that possess at least features 1-11, 31-33, the user of the electric lubricant dispenser can easily detect if gas is present in the pump (or is likely to be present).

[0074] The notification unit may notify the information in any way. The notification unit may be configured to display the information in a visible manner, for example. The notification unit may be configured to output the information by sound in a manner that is recognizable at an angle, for example.

[0075] One embodiment may include, in addition to or instead of, at least one of the features 1 to 33 described above, at least one of the following: Feature 34: The pump is configured to repeatedly perform a predetermined dispensing action for dispensing lubricant. Feature 35: The control circuit is configured to accumulate (in other words, cumulatively add up) the actual number of discharges, which is the number of times the predetermined discharge operation has been performed by the pump while the motor is running. Feature 36: The control circuit is configured to stop the motor based on the actual number of discharges reaching the target number of discharges. Feature 37: The predetermined process includes temporarily suspending the accumulation of the actual number of discharges.

[0076] An electric lubricant dispenser having at least features 1-11, 34-37 can suppress or prevent the actual amount of lubricant dispensed until the motor is stopped from being less than the amount corresponding to the target number of dispenses. The dispensing operation may include receiving the lubricant and dispensing the received lubricant.

[0077] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 37: Feature 38: The control circuit is configured to temporarily stop accumulating the actual number of discharges and then resume accumulating the actual number of discharges based on the load torque no longer meeting the first requirement.

[0078] An electric lubricant dispenser possessing at least features 1-11, 34-38 can accurately dispense an amount of lubricant corresponding to the target number of discharges, even if gas is temporarily mixed into the pump while the motor is running.

[0079] One embodiment may include, in addition to or instead of, at least one of the features 1 to 38 described above, at least one of the following: Feature 39: The pump includes a chamber configured to contain a lubricant. The chamber may be configured to contain the lubricant received by the pump. Feature 40: The pump has a discharge port that communicates with the chamber. Feature 41: The pump is equipped with a plunger. Feature 42: The plunger is (i) located within a chamber and (ii) reciprocated within the chamber by a motor to discharge the lubricant from the chamber through a discharge port. The plunger may be reciprocated by a motor (or by the driving force of a motor).

[0080] An electric lubricant dispenser having at least features 1-11, 39-42 can properly detect the ingress of gas in a plunger-type reciprocating pump. The aforementioned statement that "gas is mixed into the pump" may include the presence of gas in the chamber. If the electric lubricant dispenser is equipped with a plunger, the load torque is the torque generated by the load on the plunger, in other words, the torque consumed to make the plunger reciprocate. It may also be the torque that is expended (used). The control circuit may then perform predetermined processing based on the fact that the torque satisfies the first requirement while the motor is being driven.

[0081] The electric lubricant dispenser may include a converter that converts rotational motion into linear motion. The converter (i) is directly or indirectly connected to a motor and a reciprocating member, (ii) receives the rotation of the motor, and (iii) converts that rotation into the reciprocating motion of the reciprocating member. The converter may be one of several components that make up the pump.

[0082] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 42: Feature 43: The predetermined drive period includes the period during which the plunger makes one round trip within the chamber.

[0083] An electric lubricant dispenser having at least features 1-12, 39-43 can appropriately and efficiently detect the inclusion of gas in a plunger reciprocating pump. The aforementioned presence of gas in the pump may include (i) the presence of gas in the chamber, and / or (ii) the presence of gas in the discharge from the chamber that is about to be discharged by the plunger.

[0084] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 43: Feature 44: A predetermined discharge operation includes the plunger making one back-and-forth motion within the chamber.

[0085] An electric lubricant dispenser possessing at least features 1-11, 34-37, 39-42, and 44 can appropriately dispense an amount of lubricant corresponding to the target number of dispensing cycles. One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 44: Feature 45: The control circuit is configured to stop the motor when the load torque has remained in a state that satisfies the first requirement for a predetermined period of time while the motor is running.

[0086] In electric lubricant dispensers that possess at least features 1-11,45, the user can take appropriate action in the event of a persistent condition in which gas is present (or potentially present).

[0087] In one embodiment, the motor may be stopped without waiting for a predetermined period of time to continue once the first requirement is met. One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 45: Feature 46: The control circuit is configured to detect, in response to the first requirement being met while the motor is running, whether gas is present in the pump (or potentially present) and / or whether the pump is about to discharge the gas.

[0088] Electric lubricant dispensers possessing at least features 1-11,46 allow for various responses to be taken in response to the detection of gas contamination. In some embodiments, the lubricant may be in a semi-solid form. In some embodiments, the lubricant may contain grease. In some embodiments, the lubricant may be in a liquid or solid form.

[0089] One embodiment may include, in addition to or instead of, at least one of the above-described features 1 to 46: Feature 47: The control circuit is configured to perform predetermined processing based on whether the load torque during the period when the motor is accelerating or decelerating satisfies the first requirement.

[0090] An electric lubricant dispenser having at least features 1 to 11, 47 can properly detect the presence of gas even when the motor is accelerating or decelerating. In other words, while the motor is rotating at a constant speed, the presence of gas can be detected based on the magnitude of the current supplied to the motor. However, while the motor is accelerating, the current can change in the same way as if gas were present, even if no gas is present. Similarly, while the motor is decelerating, the current can change in the same way as if no gas were present, even if gas is present. Therefore, it is not easy, or even impossible, to detect the presence of gas based on the current during motor acceleration and deceleration.

[0091] In contrast, an electric lubricant dispenser having at least features 1 to 11, 47 can accurately detect gas contamination during motor acceleration and / or deceleration based on load torque.

[0092] One embodiment may include, in addition to or instead of, at least one of the features 1 to 47 described above, at least one of the following: Feature 48: The drive circuit is configured to supply current to the motor and rotate it. Feature 49: The control circuit is configured to perform predetermined processing during the gear change period when the motor is accelerating or decelerating, based on the fact that the load torque during the gear change period satisfies the first requirement. Feature 50: The control circuit is configured to perform predetermined processing during the constant-speed period when the motor is rotating at a constant speed, based on the fact that the magnitude of the current supplied to the motor satisfies the second requirement indicating that gas is mixed into the pump.

[0093] One embodiment may provide a method for dispensing lubricant from an electric lubricant dispenser, comprising at least one of the following: Feature 51: The pump of the electric lubricant dispenser, configured to dispense lubricant, is driven by the motor of the electric lubricant dispenser. Feature 52: Performing a predetermined process based on whether the load torque meets the requirements (or predetermined requirements) while the motor is running. Feature 53: Load torque is the torque generated by the load received from the pump, which is part of the torque applied to the motor from an external source. Feature 54: The above requirement indicates that gas is mixed into the pump.

[0094] Methods possessing features 51-54 can properly detect the presence of gas inside the pump. In one embodiment, the above features 1 to 54 may be combined in any combination.

[0095] In one embodiment, any of the above features 1 to 54 may be excluded. [2. Specific exemplary embodiments] The following exemplary embodiment provides an electric lubricant dispenser 1 shown in Figure 1. The electric lubricant dispenser 1 is configured to dispense lubricant. Specifically, the electric lubricant dispenser 1 of this embodiment is an electric grease gun configured to dispense grease.

[0096] For the sake of clarity, the directions in the electric lubricant dispenser 1 are defined as shown in Figure 1 and subsequent figures. Specifically, "up" (upward direction), "down" (downward direction), and "right" (rightward direction) ), "left" (leftward direction), "front" (forward direction), and "rear" (rearward direction) are defined. These directions are used merely to facilitate an easy understanding of the structure of the electric lubricant dispenser 1 and are not intended to limit the orientation of the electric lubricant dispenser 1. The electric lubricant dispenser 1 can be oriented in any direction.

[0097] [2-1. First Embodiment] (2-1-1) Mechanical configuration of electric lubricant dispenser As shown in Figures 1 and 2, the electric lubricant dispenser 1 of this first embodiment includes a housing 2. The housing 2 comprises a first split housing 2a and a second split housing 2b that are joined together.

[0098] The housing 2 has a motor housing 4 in its center in the height direction. The height direction corresponds to the direction from the bottom to the top or from the top to the bottom of the housing 2. In this first embodiment, the motor housing 4 is cylindrical and extends in the length direction. The length direction corresponds to the direction from the front to the rear or from the rear to the front of the housing 2. The motor housing 4 houses a motor 20. The motor 20 is an electric motor.

[0099] The housing 2 is equipped with a grip 5 on its upper part. In this first embodiment, the grip 5 extends in the longitudinal direction and is bent downward. The motor housing 4 is provided with a front coupling portion 6 at its front end. The front coupling portion 6 is coupled to the front end of the grip 5. The motor housing 4 is provided with a rear coupling portion 7 at its rear end. The rear coupling portion 7 is coupled to the rear end of the grip 5. In this first embodiment, the rear coupling portion 7 rises upward so as to form a space between the motor housing 4 and the grip 5.

[0100] The electric lubricant dispenser 1 is equipped with a trigger switch 8 housed within the grip 5. The electric lubricant dispenser 1 is also equipped with a trigger 9 for the user of the electric lubricant dispenser 1 to manually operate the trigger switch 8.

[0101] Trigger 9 is pulled by the user to drive the motor 20 (i.e., to dispense grease). Trigger 9 is configured to be displaceable between an initial position and a maximum position. When trigger 9 is not manually operated, it is in the initial position. In response to manual operation, trigger 9 moves from the initial position towards the maximum position.

[0102] When the trigger 9 is located between the initial position and the minimum position, the trigger switch 8 is off and the motor 20 is stopped. The minimum position is located between the initial position and the maximum position. When the trigger 9 is located between the minimum position and the maximum position, the trigger switch 8 is on and the motor 20 is rotatable. In this first embodiment, the trigger 9 protrudes downward from the grip 5.

[0103] The grip 5 is equipped with a light 10 on its front surface. In this first embodiment, the light 10 is equipped with a light-emitting diode (LED), which is not shown, as a light source. The grip 5 is equipped with an operation panel 70 on its front upper surface. The operation panel 70 is configured to be manually operated by the user to turn the light 10 on or off, or to change the settings of the electric lubricant dispenser 1.

[0104] The grip 5 is equipped with a first lock button 12 in front of the trigger 9. The first lock button 12 is configured to be pressed by the user to lock the trigger 9 in its maximum position. The grip 5 is equipped with a second lock button 13 below the first lock button 12. The second lock button 13 is configured to be pressed by the user to lock the trigger 9 in its initial position (i.e., unpulled position).

[0105] The rear coupling portion 7 is provided with a battery holding portion 14 at its rear end. The battery holding portion 14 is configured so that the battery pack 15 can be detachably attached to it. In this first embodiment, the battery holding portion 14 is configured such that the battery pack 15 is attached to the battery holding portion 14 by sliding the battery pack 15 from above to below at its rear end.

[0106] The battery pack 15 includes a battery (not shown) inside. In this first embodiment, the battery has a rated voltage of 36 volts. The battery pack 15 supplies power from the battery to the electric lubricant dispenser 1 via the battery holder 14.

[0107] The battery holder 14 includes a terminal block 16 inside. The terminal block 16 is configured to be electrically connected to the battery pack 15 mounted in the battery holder 14. In this first embodiment, the terminal block 16 extends in the height direction.

[0108] The battery holder 14 houses the control unit 17 in front of the terminal block 16. In this first embodiment, the control unit 17 extends in the height direction. The control unit 17 includes a control circuit board 18.

[0109] In this first embodiment, the motor 20 is an inner rotor type brushless motor (more specifically, a three-phase brushless DC motor). In another embodiment, the motor 20 may be any other type of motor (for example, a brushed DC motor).

[0110] The motor 20 includes a stator 21. The stator 21 has three lead wires 27 (Figure 2 shows only one lead wire 27). The stator 21 has a first insulator 23A at its front end. The stator 21 has a second insulator 23B at its rear end.

[0111] The stator 21 comprises three coils 24 wound around a first insulator 23A and a second insulator 23B. The second insulator 23B has six terminals (not shown) fused to the ends of the wires of these coils 24.

[0112] The second insulator 23B includes a short-circuit member 25. The short-circuit member 25 comprises three insert-molded short-circuit fittings 26 (Figure 2 shows only two short-circuit fittings 26). These short-circuit fittings 26 electrically connect the terminals of the second insulator 23B so that the coil 24 described above forms a delta configuration (or delta connection). The coil 24 described above may also form a star configuration (or star connection).

[0113] The stator 21 includes a sensor circuit board 28 between the second insulator 23B and the short-circuit member 25. The sensor circuit board 28 includes first to third rotational position sensors 28A to 28C (see Figure 6). In this first embodiment, the first to third rotational position sensors 28A to 28C are Hall sensors, but are not limited to Hall sensors. The first to third rotational position sensors 28A to 28C are connected to three signal lines 29 (Figure 2 shows only one signal line 29). The lead wires 27 and signal lines 29 are connected to the control circuit board 18 of the control unit 17.

[0114] The motor 20 has a rotor 22 inside a stator 21. The rotor 22 has a rotating shaft 30 at its center. The rotating shaft 30 has two or more permanent magnets 31 embedded in its outer circumferential wall.

[0115] The first to third rotational position sensors 28A to 28C (i) are arranged around the rotor 22 and (ii) each output first to third rotational signals corresponding to the rotational position of the rotational axis 30 (and consequently the rotational position of the rotor 22).

[0116] The rotating shaft 30 is equipped with a fan 32 attached to its front end. In this first embodiment, the fan 32 extends perpendicular to the rotating shaft 30. The rear coupling portion 7 houses the first bearing 35 behind the short-circuiting member 25. The first bearing 35 rotatably supports the rear end of the rotating shaft 30.

[0117] The motor housing 4 includes a gear housing 40 in front of the motor 20. In this first embodiment, the gear housing 40 is cylindrical. The gear housing 40 has an opening at its rear end. The gear housing 40 includes a bracket plate 41 attached to this opening. The rotating shaft 30 protrudes into the gear housing 40 through the bracket plate 41. The bracket plate 41 holds a second bearing 42. The second bearing 42 rotatably supports the front end of the rotating shaft 30.

[0118] The gear housing 40 is equipped with a spindle 44 at its front end. The gear housing 40 houses a transmission mechanism 43. The transmission mechanism 43 is connected to the rotating shaft 30 and transmits the rotation of the rotating shaft 30 to the pump 60 described later via the spindle 44. The transmission mechanism 43 is configured to (i) receive the rotation of the rotating shaft 30 and (ii) rotate the spindle 44 at a rotational speed lower than the rotational speed of the rotating shaft 30. The transmission mechanism 43 may include planetary gears.

[0119] Housing 2 includes a crank housing 45 at the front end of the gear housing 40. In this first embodiment, the crank housing 45 extends in the height direction. The spindle 44 protrudes from the gear housing 40 into the crank housing 45.

[0120] The crank housing 45 houses a crank disc 46 located at the front end of the spindle 44. The crank disc 46 is equipped with an eccentric pin 47 that protrudes forward. The crank housing 45 is equipped with a slider 48 in front of the crank disc 46. The slider 48 has an elongated hole 48A that extends in the width direction. The width direction corresponds to the direction from right to left or left to right of the housing 2. An eccentric pin 47 is inserted into the elongated hole 48A. The slider 48 is connected to a plunger 50 at the center of its lower end. The plunger 50 has an upper end connected to the slider 48 and extends downward.

[0121] The crank housing 45 includes a slider guide 49 that supports the slider 48 so that it can move up and down. The slider 48 and slider guide 49 are also shown in Figure 3. The slider 48 is movable in the height direction along the slider guide 49.

[0122] In the crank housing 45 configured in this way, when the crank disc 46 rotates together with the spindle 44, the eccentric pin 47 undergoes eccentric motion. The vertical stroke of the eccentric pin 47 causes the slider 48 to reciprocate up and down, and the plunger 50 also reciprocates up and down. In other words, the crank disc 46 and the slider 48 convert the rotational motion of the motor 20 into linear reciprocating motion.

[0123] The crank housing 45 is equipped with a front holder 51 at its lower part. The housing 2 is equipped with a rear holder 52 behind the front holder 51 and below the motor housing 4. The rear holder 52 is equipped with two legs 53 that protrude downward at its front and rear ends.

[0124] The electric lubricant dispenser 1 has a tank 54 supported by a front holder 51 and a rear holder 52. The tank 54 has an open front end. The tank 54 reaches the rear surface of the front holder 51 through the rear holder 52. The front end of the tank 54 is screwed into the rear surface of the front holder 51. In other words, the tank 54 extends longitudinally below the motor housing 4.

[0125] The tank 54 houses a rod 55. The rod 55 extends from the rear end of the tank 54 to the front end of the tank 54. The rod 55 holds the piston 56 so that it can move along the rod 55. The rod 55 has a rear end that protrudes from the tank 54. The tank 54 has a handle 57 attached to the rear end of the rod 55. The tank 54 houses a coil spring 58. The coil spring 58 is located behind the piston 56 and biases the piston 56 forward. The tank 54 houses a grease-filled cartridge (not shown) in front of the piston 56. This cartridge is pressed against the piston 56, supplying grease into the front holder 51.

[0126] The front holder 51 is equipped with a pump 60. The pump 60 is equipped with the plunger 50 described above. The pump 60 is equipped with an upper cylinder portion 60A and a lower cylinder portion 60B. The upper cylinder portion 60A and the lower cylinder portion 60B form a chamber 63. The plunger 50 is located inside the chamber 63.

[0127] Chamber 63 has an inlet hole 63A between the upper cylindrical portion 60A and the lower cylindrical portion 60B. Chamber 63 communicates with tank 54 through the inlet hole 63A. Grease is supplied from the cartridge into chamber 63 through the inlet hole 63A.

[0128] The upper cylinder portion 60A is equipped with a seal ring 61A at its top. The plunger 50 passes through the seal ring 61A. The seal ring 61A prevents or suppresses grease in the chamber 63 from leaking out of the upper cylinder portion 60A upward.

[0129] The lower cylinder portion 60B is provided with a discharge passage 66. The discharge passage 66 (i) communicates with the chamber 63 via a check valve 64 (described later), and (ii) extends in the longitudinal direction. The front holder 51 is provided with a front cylinder portion 60C at its front end. The front cylinder portion 60C protrudes forward from the front holder 51. The discharge passage 66 passes through the center of the front cylinder portion 60C. The discharge passage 66 is provided with a discharge port 66A at its front end. The front cylinder portion 60C is connected to a hose 68. Grease is discharged from the discharge port 66A through the hose 68 to the outside of the electric lubricant dispenser 1.

[0130] The pump 60 is equipped with the aforementioned check valve 64 at the bottom of the chamber 63. The check valve 64 allows grease to flow out of the chamber 63 into the discharge passage 66, while suppressing or preventing backflow of grease from the discharge passage 66 into the chamber 63.

[0131] The front cylinder portion 60C is equipped with a relief valve 69 on its right side. The relief valve 69 is configured to release the grease in the discharge passage 66 to the outside of the electric lubricant supply unit 1 when the pressure of the grease in the discharge passage 66 exceeds a predetermined pressure.

[0132] The front holder 51 is equipped with an air drain valve 67 at its front end. The air drain valve 67 is provided to release gas (e.g., air) inside the chamber 63 (more specifically near the inlet hole 63A) to the outside of the electric lubricant dispenser 1. When the air drain valve 67 is tightened, the chamber 63 is isolated from the outside of the electric lubricant dispenser 1. The electric lubricant dispenser 1 is normally used with the air drain valve 67 tightened. When the air drain valve 67 is loosened, the chamber 63 communicates with the outside of the electric lubricant dispenser 1. If gas is present in the chamber 63 at this time, that gas can be released to the outside of the electric lubricant dispenser 1 via the air drain valve 67.

[0133] (2-1-2) Mechanical operation of the electric lubricant dispenser In the electric lubricant dispenser 1 configured as described above, when the user pulls the trigger 9, the motor 20 rotates, and consequently, the rotating shaft 30 rotates.

[0134] The rotation of the rotating shaft 30 is transmitted to the spindle 44 via the transmission mechanism 43, and the crankcase 46 rotates together with the spindle 44. This causes the eccentric pin 47 to perform an eccentric motion. In response to the eccentric motion of the eccentric pin 47, (i) the slider 48 moves up and down along the slider guide 49, and (ii) this causes the plunger 50 to reciprocate up and down.

[0135] More specifically, as shown in Figure 3, the plunger 50 moves up and down through the first to fourth states in this order. Figure 3 schematically shows the position of the inlet hole 63A. The first state is when the slider 48 is in the process of moving upward. More specifically, the first state is when the slider 48 is in an intermediate position within its reciprocating range. Figure 2 shows the electric lubricant dispenser 1 in the first state. In the first state, as is clear from Figures 2 and 3, the plunger 50 is inserted into the lower cylinder portion 60B. When the motor 20 rotates further from the first state, it transitions to the second state.

[0136] The second state is when the slider 48 has reached the highest point in its reciprocating range. Before the slider 48 reaches the highest point, the lower end of the plunger 50 disengages from the lower cylinder 60B, thereby allowing grease to flow from the tank 54 into the chamber 63. In the second state, the lower end of the plunger 50 is either fully retracted into the upper cylinder 60A or slightly protruding downward from the upper cylinder 60A. If the motor 20 rotates further from the second state, the slider 48 moves downward, transitioning to the third state.

[0137] The third state is when the slider 48 is in the process of moving downward. More specifically, the third state is when the slider 48 is in an intermediate position within its reciprocating range. In the third state, as in the first state, the plunger 50 is inserted into the lower cylinder portion 60B. If the motor 20 rotates further from the third state, it transitions to the fourth state.

[0138] The fourth state is when the slider 48 has reached its lowest point in its reciprocating range. In the fourth state, the lower end of the plunger 50 has reached near the lower end of the chamber 63. If the motor 20 rotates further from the fourth state, the slider 48 moves upward and transitions to the first state.

[0139] Between the second and fourth states, the plunger 50 moves downward. During this time, the grease in the chamber 63 is pressed against the bottom surface of the plunger 50 (i.e., the lower end surface; hereinafter referred to as the "plunger lower end surface"). As a result, the grease flows into the hose 68 via the check valve 64, the discharge passage 66, and the discharge port 66A, and is discharged from the hose 68 to the outside of the electric lubricant supply unit 1.

[0140] Thus, while the motor 20 is rotating, the slider 48 (and consequently the plunger 50) moves back and forth repeatedly, causing grease to be continuously discharged (or may be discharged) from the discharge port 66A. Grease is discharged each time the plunger 50 makes one back-and-forth motion. Therefore, one back-and-forth motion of the plunger 50 can be rephrased as one grease discharge operation. One back-and-forth motion of the plunger 50 (i.e., one discharge operation) is an example of a predetermined discharge operation in the summary of the embodiment.

[0141] Note that the motor 20 may rotate in the opposite direction to the operation example in Figure 3. In this case, the plunger 50 moves up and down through the fourth to first states in that order, thereby achieving the same operation as in the operation example in Figure 3. Grease is dispensed.

[0142] (2-1-3) Details of the control panel As shown in Figure 4, the control panel 70 includes a first switch 71. In this first embodiment, the first switch 71 and the second and third switches 72 and 73, which will be described later, are push-button switches. In another embodiment, the first to third switches 71 to 73 may be other types of manual switches.

[0143] Each time the first switch 71 is briefly pressed, the rotational speed level of the motor 20 is sequentially switched to one of several rotational speed levels (for example, four levels: levels 1 to 4). For each rotational speed level, the maximum rotational speed of the motor 20 is set. The maximum rotational speed increases in the order of, for example, level 1, level 2, level 3, and level 4.

[0144] The motor 20 is rotated up to the maximum rotational speed corresponding to the set rotational speed level. Specifically, for example, the target rotational speed is set up to the maximum rotational speed, depending on the operating mode and / or the amount (i.e., position) of the trigger 9, as described later. The motor 20 is controlled to maintain a constant rotational speed (in other words, speed feedback control) so that its rotational speed (more specifically, the actual rotational speed; hereinafter referred to as "actual rotational speed") matches the target rotational speed.

[0145] When the first switch 71 is pressed and held, the light 10 turns on. After the light 10 turns on, the light 10 may turn off, for example, if (i) a predetermined time has elapsed or (ii) the first switch 71 is pressed and held again. A short press corresponds to an operation in which the switch is released before a certain period of time has elapsed since it was pressed. A long press corresponds to an operation in which the switch is pressed and held continuously for a certain period of time or longer before being released.

[0146] The control panel 70 includes a first display screen 74. The first display screen 74 displays information indicating the set rotation speed level (for example, a number from "1" to "4"). "1" to "4" represent the first to fourth levels, respectively. In this first embodiment, the first display screen 74 and the second and third display screens 75A and 75B, described later, are each 7-segment displays. In another embodiment, each of the first to third display screens 74, 75A, and 75B may be other types of display screens, including liquid crystal displays (LCDs).

[0147] The control panel 70 includes the aforementioned second switch 72 and third switch 73. Each time the second and third switches 72 and 73 are pressed simultaneously, the operating mode of the electric lubricant dispenser 1 is switched. In this first embodiment, the operating modes include a continuous discharge mode and an automatic discharge mode (or a quantitative discharge mode). In this first embodiment, each time the second and third switches 72 and 73 are pressed simultaneously, the operating mode alternately switches between the continuous discharge mode and the automatic discharge mode.

[0148] In continuous discharge mode, the motor 20 rotates continuously while the trigger 9 is pulled. In this first embodiment, the target rotational speed in continuous discharge mode changes depending on the position of the trigger 9. Specifically, the target rotational speed increases continuously or stepwise as the trigger 9 moves from the minimum position to the target arrival position. More specifically, the target rotational speed increases from a predetermined minimum value (e.g., zero) towards a maximum rotational speed corresponding to a set rotational speed level. The target arrival position may be located between the minimum and maximum positions, or it may coincide with the maximum position. When the trigger 9 reaches the target arrival position, the target rotational speed reaches the maximum rotational speed corresponding to the set rotational speed level. If the trigger 9 is located between the target arrival position and the maximum position, the target rotational speed is maintained at the maximum rotational speed. It can be done.

[0149] In addition, the target rotational speed in continuous discharge mode may be maintained at a constant rotational speed (for example, the maximum rotational speed corresponding to the set rotational speed level) regardless of the position of the trigger 9.

[0150] In automatic dispensing mode, the motor 20 starts rotating when the trigger 9 is pulled. After rotation begins, when the plunger 50 (in other words, the slider 48) has reciprocated a target number of times (in other words, when the predetermined dispensing operation has been performed a target number of times, or to put it another way, when an amount of grease corresponding to the target number of reciprocations has been dispensed), the motor 20 automatically stops, even if the trigger 9 is still pulled. The target number of reciprocations can be set to any value by the user.

[0151] In automatic dispensing mode, the target rotational speed is set to a constant rotational speed (for example, the maximum rotational speed corresponding to the set rotational speed mode) regardless of the position of trigger 9. However, the target rotational speed in automatic dispensing mode may change depending on the position of trigger 9, similar to continuous dispensing mode.

[0152] The control panel 70 is equipped with a setting count display screen 75. The setting count display screen 75 (i) comprises the aforementioned second display screen 75A and third display screen 75B, and (ii) is capable of displaying a two-digit number. When the operating mode is set to automatic discharge mode, the target number of round trips is displayed on the setting count display screen 75.

[0153] In this first embodiment, in automatic dispensing mode, any target number of round trips can be set, up to a predetermined maximum set number of 99 or less. The user can set the target number of round trips to any value by operating the second switch 72 or the third switch 73. Specifically, in automatic dispensing mode, each time the second switch 72 is pressed, the target number of round trips increases by one, and the increased target number of round trips is set as the new target number of round trips and displayed on the set number display screen 75. Conversely, in automatic dispensing mode, each time the third switch 73 is pressed, the target number of round trips decreases by one, and the decreased target number of round trips is set as the new target number of round trips and displayed on the set number display screen 75. The maximum set number of round trips can be determined in any way and may be set to 100 or more.

[0154] (2-1-4) Electrical configuration of the electric lubricant dispenser Referring to Figure 5, the electrical configuration of the electric lubricant dispenser 1 will be described. The electric lubricant dispenser 1 includes a control circuit board 18 with a ground. The electric lubricant dispenser 1 includes a power line Lp extending from the positive terminal of the battery pack 15 mounted in the battery holder 14 to the control circuit board 18. The electric lubricant dispenser 1 includes a ground line Ln extending from the negative terminal of the battery pack 15 mounted in the battery holder 14 to the ground on the control circuit board 18. The battery pack 15 applies its rated voltage between the power line Lp and the ground line Ln.

[0155] The electric lubricant dispenser 1 includes a power supply circuit 84. In this first embodiment, the power supply circuit 84 is located on the control circuit board 18. The power supply circuit 84 is connected to the power line Lp and to ground. The power supply circuit 84 generates a fixed DC voltage (hereinafter referred to as "power supply voltage") Vc based on the battery voltage supplied from the battery pack 15.

[0156] The electric lubricant dispenser 1 includes a control circuit 80. The control circuit 80 is located on a control circuit board 18 and operates in response to a power supply voltage Vc. The control circuit 80 is a microcomputer comprising a CPU 80A and a semiconductor memory 80B. The semiconductor memory 80B includes ROM, RAM, and rewritable non-volatile memory. The non-volatile memory is, for example, E These include EPROM, flash memory, ReRAM, FeRAM, etc. The various functions of the control circuit 80 are realized by the CPU 80A executing a program stored in the semiconductor memory 80B. When the CPU 80A executes this program, the method corresponding to this program is executed.

[0157] In another embodiment, the control circuit 80 may include an additional microcomputer. In yet another embodiment, some or all of the functions achieved by the CPU 80A may be achieved by one or more electronic components (e.g., integrated circuits). In yet another embodiment, the control circuit 80 may be a logic circuit (or wired logic connection) including two or more electronic components. In yet another embodiment, the control circuit 80 may include an ASIC and / or ASSP. In yet another embodiment, the control circuit 80 may include a programmable logic device on which a reconfigurable logic circuit can be constructed. An example of a programmable logic device is an FPGA.

[0158] The electric lubricant dispenser 1 includes a drive circuit 82 configured to drive the motor 20 by supplying current (hereinafter referred to as "motor current") to the motor 20. The drive circuit 82 is electrically connected to the power line Lp and the ground line Ln. The drive circuit 82 (i) receives the battery voltage and (ii) generates a three-phase voltage (i.e., generates three-phase power) from the battery voltage and supplies it to the motor 20. In this first embodiment, the drive circuit 82 is located on the control circuit board 18.

[0159] The drive circuit 82 is a three-phase full-bridge circuit, but is not limited to a three-phase full-bridge circuit. The drive circuit 82 includes first to third switches Q1 to Q3 located on the high side and fourth to sixth switches Q4 to Q6 located on the low side. The first to third switches Q1 to Q3 are connected to the power line Lp and the corresponding lead wires 27 of the motor 20, respectively, and function as so-called high-side switches. The fourth to sixth switches Q4 to Q6 are connected to the corresponding lead wires 27 and ground, respectively, and function as so-called low-side switches.

[0160] The first to sixth switches Q1 to Q6 each receive the first to sixth drive control signals from the control circuit 80 and turn on or off according to the respective drive control signals they receive. In this first embodiment, the first to sixth drive control signals may be pulse width modulated signals. The first to sixth switches Q1 to Q6 are semiconductor switches. Examples of semiconductor switches include field-effect transistors (FETs), bipolar transistors, and insulated-gate bipolar transistors (IGBTs).

[0161] When the motor 20 is driven, basically one of the high-side switches and one of the low-side switches are turned on. As a result, motor current flows from the positive terminal of the battery through the high-side switch, the motor 20, and the low-side switch to the negative terminal of the battery, causing the motor 20 to rotate.

[0162] The electric lubricant dispenser 1 is equipped with a current detector 93. The current detector 93 is located on the current path connecting the drive circuit 82 to the negative terminal of the battery. The current detector 93 outputs a current detection signal to the control circuit 80 that corresponds to the magnitude of the motor current flowing through this current path.

[0163] The electric lubricant dispenser 1 is equipped with a sliding resistor 81 having a lever 81A. The lever 81A has a displaceable first end and a second end connected to the control circuit 80. The sliding resistor 81 has a resistance value that changes according to the position of the first end of the lever 81A. The second end of the lever 81A outputs a voltage (hereinafter referred to as the "trigger voltage") of a magnitude corresponding to the resistance value to the control circuit 80. The first end of the lever 81A is in a range from the initial position to the maximum position. The sliding resistor 81 is displaced according to the position of the trigger 9. For example, the resistance value of the sliding resistor 81 is minimum when the trigger 9 is in its initial position and increases as the trigger 9 moves from the initial position towards the maximum position.

[0164] The electric lubricant dispenser 1 is equipped with first to fourth pull-up resistors R1 to R4. In this first embodiment, the first to fourth pull-up resistors R1 to R4 are located on the control circuit board 18. Each of the first to fourth pull-up resistors R1 to R4 has a first terminal connected to the power supply circuit 84 to receive the power supply voltage Vc from the power supply circuit 84. The first pull-up resistor R1 has a first terminal connected to the trigger switch 8 and a second terminal connected to the control circuit 80. The second pull-up resistor R2 has a first terminal connected to the first switch 71 and a second terminal connected to the control circuit 80. The third pull-up resistor R3 has a first terminal connected to the second switch 72 and a second terminal connected to the control circuit 80. The fourth pull-up resistor R4 has a first terminal connected to the third switch 73 and a second terminal connected to the control circuit 80. Each of the trigger switch 8, the first switch 71, the second switch 72, and the third switch 73 has a second terminal connected to ground on the control circuit board 18.

[0165] When the trigger switch 8, the first switch 71, the second switch 72, and the third switch 73 are off, the second terminals of the first to fourth pull-up resistors R1 to R4 have a voltage at the same level as the power supply voltage Vc (i.e., a high level). When the trigger switch 8, the first switch 71, the second switch 72, and the third switch 73 are on, the second terminals of the first to fourth pull-up resistors R1 to R4 have a voltage at the same level as ground (i.e., a low level). The first to fourth pull-up resistors R1 to R4 may have the same resistance value or may have different resistance values.

[0166] The control circuit 80 can detect whether the trigger 9, the first switch 71, the second switch 72, and the third switch 73 are being operated manually, based on the voltages at the second terminals of the first to fourth pull-up resistors R1 to R4. Specifically, if the voltages at the second terminals of the first to fourth pull-up resistors R1 to R4 are at a high level, the control circuit 80 detects that the trigger 9, the first switch 71, the second switch 72, and the third switch 73 are not being operated manually. If the voltages at the second terminals of the first to fourth pull-up resistors R1 to R4 are at a low level, the control circuit 80 detects that the trigger 9, the first switch 71, the second switch 72, and the third switch 73 are being operated manually.

[0167] The control circuit board 18 is connected to the first to third display screens 74, 75A, and 75B of the operation panel 70. The first to third display screens 74, 75A, and 75B operate by receiving a power supply voltage Vc from the control circuit board 18. In addition, the first to third display screens 74, 75A, and 75B each receive the first to third display control signals from the control circuit 80 and display information.

[0168] The control circuit board 18 is connected to the sensor circuit board 28. The first to third rotational position sensors 28A to 28C on the sensor circuit board 28 operate by receiving a power supply voltage Vc from the control circuit board 18. The first to third rotational position sensors 28A to 28C are connected to the control circuit 80 via a signal line 29 and output the first to third rotational signals to the control circuit 80. The first to third rotational signals are associated with each of the three phases of the motor 20 (i.e., U phase, V phase, and W phase). The first to third rotational signals are, for example, sinusoidal signals. The voltage of each of the first to third rotational signals reverses from positive to negative or negative to positive each time the rotor 22 rotates 180 degrees in electrical angle. The first to third rotational signals have a phase difference of 120 degrees in electrical angle from each other.

[0169] In another embodiment, the sensor circuit board 28 may be configured to output a single rotation detection signal (e.g., a pulse signal) to the control circuit 80 instead of the first to third rotation signals. The rotation detection signal changes every time the rotor 22 rotates by 60 degrees in electrical angle.

[0170] The electric lubricant dispenser 1 includes a temperature sensor 100 connected to a control circuit 80. The temperature sensor 100 is provided to detect the temperature of the electric lubricant dispenser 1. More specifically, the temperature sensor 100 is provided to directly or indirectly detect the temperature of the grease. The temperature sensor 100 outputs a temperature detection signal indicating the detected temperature to the control circuit 80. The temperature sensor 100 may be in any form capable of detecting temperature. The temperature sensor 100 may include, for example, a positive temperature coefficient (PTC) thermistor, a negative temperature coefficient (NTC) thermistor, or a critical temperature resistor (CTR) thermistor.

[0171] The temperature sensor 100 may be positioned in any location that allows it to directly or indirectly detect the temperature (or level) of the grease. For example, the temperature sensor 100 may be positioned in a location that allows it to directly contact the grease. More specifically, the temperature sensor 100 may be positioned, for example, at the inlet of the pump 60 (e.g., the inlet hole 63A).

[0172] Alternatively, the temperature sensor 100 may be positioned in a location that does not come into contact with the grease. Specifically, the temperature sensor 100 may be positioned, for example, on the surface or inside the grip 5, around the front holder 51, or near the tank 54 in the housing 2.

[0173] (2-1-5) Functional configuration of an electric lubricant dispenser Referring to Figure 6, the functions of the control circuit 80 will be explained. The control circuit 80 includes the functions of a pull amount detection unit 77, a switch detection unit 78, a round trip count setting unit 83, a round trip count calculation unit 79, a display control unit 85, a speed setting unit 86, an operation mode setting unit 87, a timing unit 88, a round trip determination unit 89, an air entrapment detection unit 90, an operation control unit 91, and a motor drive control unit 92. In this first embodiment, these functions are incorporated into the control circuit 80 by software. In other words, these functions are realized by the CPU 80A executing the corresponding program (specifically, the main processing described later).

[0174] In another embodiment, at least one of the following functions may be incorporated into the control circuit 80 by hardware (electronic circuitry) rather than software: the pull amount detection unit 77, the switch detection unit 78, the number of round trips setting unit 83, the number of round trips calculation unit 79, the display control unit 85, the speed setting unit 86, the operation mode setting unit 87, the timing unit 88, the round trip determination unit 89, the air lock detection unit 90, the operation control unit 91, and the motor drive control unit 92.

[0175] The pull amount detection unit 77 receives a trigger voltage from the sliding resistor 81. Based on the trigger voltage, the pull amount detection unit 77 detects the actual pull amount of the trigger 9. The actual pull amount is the actual pull amount (i.e., the actual position). If the magnitude of the trigger voltage corresponds to the initial position of the trigger 9, the pull amount detection unit 77 detects an actual pull amount of zero. If the magnitude of the trigger voltage corresponds to the maximum position of the trigger 9, the pull amount detection unit 77 detects an actual pull amount of the maximum value. If the magnitude of the trigger voltage corresponds to an intermediate position of the trigger 9, the pull amount detection unit 77 detects an actual pull amount between zero and the maximum value. The intermediate position is between the initial position and the maximum position. The pull amount detection unit 77 outputs the detected actual pull amount to the speed setting unit 86.

[0176] The switch detection unit 78 detects the change from off to on and from on to off for each of the trigger switch 8, the first switch 71, the second switch 72, and the third switch 73. In response to the trigger switch 8 changing from off to on, the switch detection unit 78 detects the change from off to on. The first signal is output to the operation control unit 91 and the round-trip count calculation unit 79. The first signal indicates that the trigger switch 8 has changed from off to on. The switch detection unit 78 outputs a second signal to the operation control unit 91 and the round-trip count calculation unit 79 in response to the trigger switch 8 changing from on to off. The second signal indicates that the trigger switch 8 has changed from on to off. The switch detection unit 78 outputs a third signal to the operation mode setting unit 87 in response to the first switch 71 changing from off to on. The third signal indicates that the first switch 71 has changed from off to on. The switch detection unit 78 outputs a fourth signal to the operation mode setting unit 87 in response to the simultaneous on-up of the second switch 72 and the third switch 73. Simultaneous on-up means that they change from off to on at the same time or approximately at the same time. The fourth signal indicates that the simultaneous on-up of the second switch 72 and the third switch 73 has occurred.

[0177] The switch detection unit 78 outputs a fifth signal to the round-trip count setting unit 83 in response to the change of the second switch 72 from off to on while the third switch 73 is off. The fifth signal indicates that the second switch 72 has changed from off to on. The switch detection unit 78 outputs a sixth signal to the round-trip count setting unit 83 in response to the change of the third switch 73 from off to on while the second switch 72 is off. The sixth signal indicates that the third switch 73 has changed from off to on.

[0178] The operation mode setting unit 87 sets the rotation speed level of the motor 20 according to the input third signal. Specifically, each time the third signal is input, the operation mode setting unit 87 changes the rotation speed level in the following order: first level → second level → third level → fourth level → first level...

[0179] The operation mode setting unit 87 sets the operation mode of the electric lubricant dispenser 1 to either continuous discharge mode or quantitative discharge mode in response to the input of the fourth signal. Specifically, each time the fourth signal is input, the operation mode setting unit 87 alternately switches the operation mode between continuous discharge mode and quantitative discharge mode.

[0180] The operation mode setting unit 87 outputs the set operation mode to the speed setting unit 86, the number of reciprocations setting unit 83, the number of reciprocations calculation unit 79, and the operation control unit 91. Note that in Figure 6, the arrows from the operation mode setting unit 87 to the number of reciprocations setting unit 83 and the number of reciprocations calculation unit 79 are omitted. The operation mode setting unit 87 outputs the set rotation speed level to the speed setting unit 86 and the display control unit 85. Note that in Figure 6, the arrows from the operation mode setting unit 87 to the display control unit 85 are omitted.

[0181] The speed setting unit 86 sets the target rotational speed of the motor 20 based on the input actual grease dispensing amount, rotational speed level, and operating mode. It then notifies the operation control unit 91 and the air entrainment detection unit 90 of the set target rotational speed. The rotational speed of the motor 20 is proportional to the discharge speed. The discharge speed is the speed at which grease is discharged from the discharge port 66A, in other words, the amount of grease discharged per unit time. Therefore, setting the target rotational speed is equivalent to setting a target value for the discharge speed.

[0182] Specifically, when the operating mode is continuous discharge mode, the speed setting unit 86 sets the target rotational speed to a value within the settable range that corresponds to the actual discharge amount. The settable range is from the minimum value (e.g., zero) to the maximum rotational speed corresponding to the rotational speed level. On the other hand, when the operating mode is quantitative discharge mode, the speed setting unit 86 maintains the target rotational speed at a constant speed (e.g., the maximum rotational speed corresponding to the rotational speed level).

[0183] In this first embodiment, when the motor 20 is started, the target rotational speed is not immediately set to a predetermined value, but gradually increases toward the predetermined value. The predetermined value is the continuous discharge value. In the mode, the target rotational speed is determined by the position of the trigger 9, and in the automatic discharge mode, it is the aforementioned constant target rotational speed. However, the target rotational speed may be immediately set to a predetermined value when the motor 20 is started.

[0184] The reciprocating count setting unit 83 sets the target number of reciprocating motions of the plunger 50 (in other words, the target number of dispensing operations) based on the input fifth and sixth signals when the operating mode is quantitative dispensing mode. Specifically, each time the fifth signal is input, the reciprocating count setting unit 83 increases the target number of reciprocating motions by one from the current value. Each time the sixth signal is input, the reciprocating count setting unit 83 decreases the target number of reciprocating motions by one from the current value. The target number of reciprocating motions may always be maintained at the latest value. Alternatively, it may be set to an initial value (e.g., zero) each time the battery pack 15 is attached to the electric lubricant dispenser 1 (i.e., each time the control circuit 80 is started). In this first embodiment, the target number of reciprocating motions is set to, for example, one of 0 to 99. The reciprocating count setting unit 83 outputs the set target number of reciprocating motions to the reciprocating count calculation unit 79. The target number of reciprocating motions is an example of the target number of dispensing operations in the summary of the embodiment.

[0185] The reciprocating determination unit 89 receives first to third rotation signals from first to third rotation position sensors 28A to 28C. Based on the first to third rotation signals, the reciprocating determination unit 89 counts the number of rotations of the motor 20. Based on the number of rotations of the motor 20 and the reduction ratio of the transmission mechanism 43, the reciprocating determination unit 89 determines whether the plunger 50 has completed one reciprocating motion (i.e., whether one discharge operation has been performed). Each time the reciprocating determination unit 89 determines that the plunger 50 has completed one reciprocating motion (i.e., one discharge operation has been performed), it outputs a reciprocating determination signal to the reciprocating count calculation unit 79 and the air entrapment detection unit 90.

[0186] The air lock detection unit 90 detects air lock when the operating mode is set to quantitative discharge mode. However, the air lock detection unit 90 may also detect air lock when the operating mode is set to continuous discharge mode. Due to various factors, gas (e.g., air or its bubbles) may enter the chamber 63. Gas may enter, for example, when attaching or detaching the cartridge. Alternatively, gas may be present in the cartridge from the beginning along with the grease.

[0187] If gas enters the chamber 63, the gas will expand and compress repeatedly as the plunger 50 moves back and forth. As a result, the check valve 64 may not open (or may not open easily) when the plunger 50 descends, and grease may not be discharged (or may not be discharged easily). Air entrapment refers to this situation, and / or the presence of gas in the chamber 63 itself, and / or the state in which the pump 60 is attempting to discharge that gas.

[0188] The air lock detection unit 90 notifies the reciprocation count calculation unit 79, the display control unit 85, the timing unit 88, and the operation control unit 91 of the air lock detection result. Specifically, the air lock detection unit 90 determines whether or not air lock has occurred each time the plunger 50 makes one reciprocation. If it determines that air lock has not occurred, it sets the air lock detection state to "not detected," and if it detects that air lock has occurred, it sets the air lock detection state to "detected." The reciprocation count calculation unit 79, the display control unit 85, the timing unit 88, and the operation control unit 91 can recognize whether or not air lock has occurred based on the set air lock detection state.

[0189] Air lock-in can be detected based on the motor current value (hereinafter referred to as "motor current value") under certain conditions. The detection of air lock-in based on the motor current value will be explained with reference to Figures 7 and 8. In Figures 7 and 8, the steady state is a state in which the target rotational speed is maintained at a constant level, and the actual rotational speed follows that target rotational speed (i.e., it is rotating at a constant speed or can be considered to be rotating at a constant speed). Furthermore, in the following explanation, "normal state" refers to a state in which no air lock-in occurs, and "air lock-in state" refers to a state in which air lock-in occurs. This indicates a jamming condition. Note that each of the multiple "plunger one-round cycle timings" in Figure 7 is the timing when the plunger 50 reaches a predetermined position (e.g., the highest position) in that one round cycle. The same applies to the "plunger one-round cycle timings" in Figures 8, 10, 11, 19, and 20.

[0190] In a steady state, the fluctuation in motor current value under normal conditions (see Figure 8) is greater than the fluctuation in motor current value under air-locked conditions (see Figure 7). Therefore, air lock can be detected, for example, based on the magnitude of the fluctuation in motor current value.

[0191] On the other hand, during the acceleration period of motor 20, the motor current value increases to accelerate motor 20, and the motor current value may fluctuate irregularly in order to keep up with the target rotational speed. In particular, when motor 20 is started, an irregular and large fluctuating current (so-called starting current) flows through motor 20, as illustrated in Figure 7. Therefore, it is difficult or impossible to detect air entrapment based on the motor current value during the acceleration period. The acceleration period basically refers to the period during which the target rotational speed is increasing, and includes the period from startup until a specified time has elapsed, or from startup until the plunger 50 has reciprocated a specified number of times. The period during which the motor is intermittently accelerating to keep up with the target rotational speed, which is included in the actual rotational speed in the steady state in Figure 8, is not included in the acceleration period referred to here.

[0192] Furthermore, during the deceleration period of motor 20, the current supplied from the battery to motor 20 decreases or becomes zero. Therefore, as is clear from Figure 8, even if air entrapment does not occur, the magnitude and fluctuation of the motor current value during deceleration are both small, making it difficult to distinguish from the motor current value in the air entrapment state (see steady state in Figure 7). For this reason, detecting air entrapment based on the motor current value during the deceleration period is difficult or impossible. Note that the deceleration period basically refers to the period during which the target rotational speed is decreasing. The period during which the motor is intermittently decelerating to follow the target rotational speed, which is included in the actual rotational speed in the steady state in Figure 8, is not included in the deceleration period referred to here. The acceleration period and deceleration period are examples of the gear shifting period in the summary of the embodiment.

[0193] Thus, during the acceleration and deceleration periods of the motor 20, detecting air entrapment based on the motor current value is difficult or impossible. Therefore, in this first embodiment, the air entrapment detection unit 90 detects air entrapment based on the load torque, which is one of the torques applied to the motor 20 from the outside. The method for detecting air entrapment based on load torque will be described in detail below.

[0194] First, the definitions of the terms "load torque" mentioned above, and "driving torque," "external input torque," "pump load," "plunger load," "mechanical loss torque," "inertia torque," and "load-inclusive torque" used in the following explanation, will be explained with reference to Figure 9.

[0195] "Drive torque" (see Figure 9) is the torque output by the motor 20. The motor 20 outputs drive torque when it receives motor current. The drive torque can be expressed using the motor current value and the motor torque coefficient (see Figure 9), as will be described later.

[0196] "External input torque" is the torque applied to the motor 20 from the outside. External input torque can be considered equal to the drive torque. In this first embodiment, the external input torque can be decomposed into load torque (see Figure 9), mechanical loss torque (see Figure 9), and inertia torque. In other words, both the external input torque and the drive torque can be considered equal to the sum of the load torque, mechanical loss torque, and inertia torque.

[0197] "Pump load" (see Figure 9) is the load received by the motor 20 from the pump 60. It is a load. The "plunger load" (see Figure 9) is part or all of the pump load and is the load received from the plunger 50. Much of the plunger load is caused by the pressure the plunger 50 receives from the grease when it descends (i.e., when the grease is discharged). If the mechanical losses in the pump 60 are small or negligible, the pump load can be said to be equal to the plunger load.

[0198] The pump load fluctuates according to the operation of the pump 60. Specifically, the pump load increases when the plunger 50 descends and decreases when the plunger 50 rises. In other words, the pump load fluctuates periodically. One cycle of fluctuation corresponds to one round trip of the plunger 50. However, the magnitude of this fluctuation differs depending on whether or not the pump 60 is in an air-locked state. In the case of an air-locked state, the pressure exerted on the plunger 50 by the grease is smaller than in the normal state. Therefore, in the case of an air-locked state, the increase in the pump load during grease discharge is suppressed, and as a result, the fluctuation in the pump load is also reduced.

[0199] "Load torque" (see Figure 9) is the torque generated by the pump load. Load torque can be said to be the torque used (consumed) for the operation of the pump 60 from the driving torque. If the mechanical losses in the pump 60 are small or negligible, load torque can be said to be the torque used for the operation of the plunger 50 (in other words, for receiving and discharging grease).

[0200] "Mechanical loss torque" (see Figure 9) is the torque applied to the motor 20 mainly due to mechanical losses in the transmission mechanism 43 (e.g., gear friction). Mechanical loss torque can be described as the torque used to counteract friction in the transmission mechanism 43, or in other words, the torque that is lost (consumed) as mechanical loss in the transmission mechanism 43.

[0201] The mechanical loss torque is generally constant if the operating environment is constant. Typically, the time required for one discharge operation (i.e., the time from when the trigger switch 8 is turned on until it is turned off) is several seconds to several tens of seconds. It is not usually likely that the operating environment will change (for example, the temperature will change) in such a short time. Therefore, it can be assumed that one discharge operation is basically performed under constant operating conditions. Thus, in this first embodiment, the mechanical loss torque is considered to be constant.

[0202] "Inertial torque" (or acceleration torque) is the torque applied to the motor 20 due to the moment of inertia around the motor 20's rotation axis 30 (see Figure 9). The moment of inertia is due to the mechanical characteristics of the entire drive force transmission system, from the motor 20 to the pump 60 (specifically the plunger 50), through which the driving torque of the motor 20 is transmitted. Inertial torque can be obtained, for example, by multiplying the moment of inertia by the acceleration (i.e., angular acceleration) of the motor 20 (see Figure 9). Inertial torque can be said to be the torque used to accelerate the motor 20 from the driving torque.

[0203] "Load-inclusive torque" is a part of the external input torque that includes at least the load torque and at least indicates the variation in the load torque. In other words, the variation in load-inclusive torque can be considered as the variation in load torque. When load-inclusive torque includes only the load torque, it directly indicates the magnitude and variation of the load torque.

[0204] The load-included torque may be the load torque with a predetermined (e.g., constant or approximately constant) bias applied to it. Specifically, the load-included torque may include both the load torque and the mechanical loss torque. Such a load-included torque can be understood as the load torque with a bias applied by the mechanical loss torque. This directly shows the fluctuation of the load torque and indirectly shows the magnitude of the load torque.

[0205] If the mechanical loss torque is known in advance, the variation in load torque and the load torque itself can be obtained from the load-included torque. Even if the mechanical loss torque is unknown, the variation in load torque can be obtained from the load-included torque.

[0206] Next, we will explain the method for detecting air lock. As mentioned above, the pump load and its fluctuations in an air lock state are smaller than the pump load and its fluctuations in a normal state. Therefore, the load torque and its fluctuations in an air lock state are smaller than the load torque and its fluctuations in a normal state. For this reason, air lock can be detected based on the load torque or its fluctuations. In addition, in this first embodiment, since the mechanical loss torque can be considered constant, air lock can be detected based on the load-inclusive torque or its fluctuations.

[0207] Load torque and load-inclusive torque can be estimated by calculation. That is, the drive torque can be expressed using the motor current value, as described above. Specifically, the drive torque can be expressed by the following equation (3).

[0208]

number

[0209] Motor torque coefficient K τ This is the torque coefficient of motor 20. The torque coefficient is also commonly called the torque constant. Drive torque τ mcan also be represented by using the external input torque as described above. Specifically, the driving torque τ m can be expressed by the following formula (4).

[0210]

Equation

[0211] Note that the first term on the right side of the above formula (4) is the inertia torque described above. In the following description, the symbol of the motor acceleration in the above formula (4) will be simplified and denoted as "ν m ". From the above formulas (3) and (4), the load torque τ out and the load-inclusive torque τ a can be expressed by the following formulas (5) and (6), respectively.

[0212]

Equation

[0213] Here, the motor torque coefficient K τ and the moment of inertia J can be identified (i.e., known) from the characteristics of the above-mentioned driving force transmission system including the motor. Therefore, if the motor current value I m and the motor acceleration ν m are known, the load-inclusive torque τ a can be calculated (i.e., estimated) based on the above formula (6).

[0214] Also, the mechanical loss torque τ loss is constant and identifiable (i.e., known) in this first embodiment. Therefore, if the motor current value I m and the motor acceleration ν m are known, the load torque τ out can be calculated (i.e., estimated) based on the above formula (5). The variation of the load-inclusive torque τ a directly represents the variation of the load torque τ out .

[0215] In the following explanation, the load torque τ calculated based on equation (5) above is used. out , and the load-inclusive torque τ calculated based on the above formula (6) a The load torque τ included out This is referred to as "estimated torque."

[0216] Motor acceleration ν m The motor acceleration may be calculated (obtained) in any way. For example, the motor acceleration may be calculated based on the actual rotational speed (for example, by differentiating it). Alternatively, for example, an acceleration detector that directly measures the motor acceleration may be provided, and the motor acceleration may be obtained from that acceleration detector.

[0217] As is clear from comparing Figure 10 and Figure 11, in the air-caught state (Figure 10), the maximum estimated torque is small, and the fluctuation of the estimated torque is also small, both during startup and in the steady state. Although not shown in Figure 10, the estimated torque and its fluctuation are also small during deceleration. On the other hand, in the normal state (Figure 11), the maximum estimated torque is large, and the fluctuation of the estimated torque is also large, both during steady state and in the deceleration. Although not shown in Figure 11, the estimated torque and its fluctuation are also large during acceleration (similar to the steady state, for example).

[0218] Therefore, if an estimated torque is obtained during the steady state, acceleration period, or deceleration period, air entrapment can be detected in various ways based on that estimated torque. Specifically, air entrapment can be detected based on (i) the magnitude of the estimated torque, (ii) the amplitude of the estimated torque, or (iii) the derivative of the estimated torque. In this first embodiment, the method for detecting air entrapment based on the magnitude of the estimated torque will be described in detail, and the detection methods based on amplitude or derivative will be described in the second and third embodiments described later.

[0219] The air lock detection unit 90 of this first embodiment determines that air lock has occurred based on the estimated torque meeting a first requirement. The first requirement may be any requirement that indicates (or makes it possible to determine) that air lock has occurred or is likely to have occurred. In other words, the first requirement may be any requirement that indicates that gas is mixed into the pump 60 (specifically, for example, the chamber 63) or is likely to be mixed in.

[0220] The first requirement of this first embodiment includes that the maximum value of the estimated torque within a predetermined driving period is less than or equal to a first threshold. If this condition is met, the first requirement is satisfied and it is determined that air has entered the system. The predetermined drive period can be any period during the operation of the motor 20. In this first embodiment, the predetermined drive period is the period during which the plunger 50 completes one reciprocating motion. The air entry detection unit 90 determines whether or not air has entered the system based on the maximum value of the estimated torque during that reciprocating motion and a first threshold value each time the predetermined drive period has elapsed (i.e., each time the plunger 50 completes one reciprocating motion).

[0221] The first threshold may be determined to be smaller than the range of estimated torque expected under normal conditions (e.g., its minimum value) and larger than the range of estimated torque expected under air entrapment conditions (e.g., its maximum value). The first threshold may be determined in any way.

[0222] The first threshold value may be a constant value, or it may be set variably according to the operating state of the electric lubricant dispenser 1. In this first embodiment, the first threshold value is set variably according to the operating state. In this first embodiment, the operating state includes the target rotational speed. That is, the air entrainment detection unit 90 sets a first threshold according to the current target rotational speed notified by the speed setting unit 86. The estimated torque and its fluctuations may increase as the target rotational speed increases. Therefore, the first threshold may be set such that it increases as the target rotational speed increases, for example, as illustrated in Figure 12.

[0223] Note that the operating state may include the actual rotational speed. That is, the first threshold value may be set according to the actual rotational speed itself. In that case as well, the first threshold value may be set in the same manner as the setting method according to the target rotational speed. For example, the horizontal axis in FIG. 12 may be read as the actual rotational speed.

[0224] Also, the operating state may include the aforementioned duty ratio. That is, the first threshold value may be set according to the duty ratio. The first threshold value may change in any way according to the duty ratio. For example, the first threshold value may be set so that the first threshold value increases as the duty ratio increases. For example, the horizontal axis in FIG. 12 may be read as the duty ratio.

[0225] Also, the operating state may include the device temperature. That is, the first threshold value may be set according to the device temperature. The device temperature is the temperature of the electric lubricant feeder 1. Specifically, the device temperature may be the temperature of the grease or a temperature indirectly indicating the temperature of the grease.

[0226] The viscosity of the grease changes depending on the temperature of the grease. For example, as the temperature of the grease increases, the viscosity of the grease decreases (i.e., it becomes softer). When the viscosity of the grease decreases, the pump load (especially the plunger load) decreases, whereby the estimated torque and its variation become smaller. Therefore, for example, the first threshold value may be set so that the first threshold value decreases as the temperature of the grease increases. The air biting detection unit 90 may receive a temperature detection signal from the temperature sensor 100 and set the first threshold value according to the temperature indicated by the temperature detection signal.

[0227] The timing unit 88 measures the air biting duration when air biting occurs. The air biting duration is the time during which air biting continuously occurs. Specifically, when the air biting detection state changes from "not detected" to "detected", the timing unit 88 starts measuring the air biting duration. Specifically, the count value is incremented (accumulated) one by one for each control cycle. When the air biting duration reaches a predetermined time (that is, when the count value reaches a predetermined value), it notifies the operation control unit 91 that the air biting has continued for the predetermined time. Specifically, the timing unit 88 sets the air biting continuous state to "detected".

[0228] The reciprocation number calculation unit 79 calculates the actual reciprocation number of the plunger 50 when the operation mode is the quantitative discharge mode. However, the reciprocation number calculation unit 79 may also calculate the actual reciprocation number when the operation mode is the continuous discharge mode. The actual reciprocation number is the actual reciprocation number of the plunger 50. In other words, the actual reciprocation number is the number of times the discharge operation has actually been performed. Therefore, the actual reciprocation number can be regarded as the actual discharge number. The actual reciprocation number is an example of the actual discharge number in the summary of the embodiment. The reciprocation number calculation unit 79 accumulates (i.e., accumulates) the actual reciprocation number each time it receives a reciprocation determination signal from the reciprocation determination unit 89 (that is, each time the plunger 50 makes one reciprocation). Specifically, each time the reciprocation number calculation unit 79 receives a reciprocation determination signal, it updates the actual reciprocation number to a value increased by "1" from the current value.

[0229] However, while the air biting is detected by the air biting detection unit 90 (that is, while the air biting detection state is set to "detected"), the reciprocation number calculation unit 79 does not update the actual reciprocation number. That is, the accumulation of the actual reciprocation number is temporarily stopped. When the air biting is eliminated and the air biting detection state is set to "not detected", the accumulation of the actual reciprocation number resumes from the value at the time of temporary stop.

[0230]

[0231] ​The round-trip count calculation unit 79 notifies the display control unit 85 of the current actual number of round trips. Furthermore, the round-trip count calculation unit 79 outputs the round-trip count difference to the operation control unit 91. The round-trip count difference is the difference between the target number of round trips and the current actual number of round trips.

[0232] In continuous discharge mode, the operation control unit 91 commands the motor drive control unit 92 to drive the motor 20 while the trigger switch 8 is ON. Specifically, the operation control unit 91 outputs a drive command to the motor drive control unit 92 and notifies it of the current target rotational speed. The drive command requests that the motor 20 be driven.

[0233] In quantitative dispensing mode, the motion control unit 91 commands the motor drive control unit 92 to drive the motor 20 while the trigger switch 8 is ON. Specifically, the motion control unit 91 outputs a drive command to the motor drive control unit 92 and notifies it of the current target rotational speed. When the reciprocating count difference notified by the reciprocating count calculation unit 79 reaches zero, the motion control unit 91 stops outputting the drive command and stops the motor 20.

[0234] When operating in quantitative discharge mode, if the timing unit 88 detects a continuous air lock condition (i.e., if air lock occurs for a predetermined period of time), the operation control unit 91 stops the output of the drive command and stops the motor 20, even if the trigger switch 8 is ON and the difference in the number of reciprocating cycles has not yet reached zero.

[0235] The motor drive control unit 92 calculates the rotational position (specifically the electrical angle) and actual rotational speed of the motor 20 based on the first to third rotational signals from the first to third rotational position sensors 28A to 28C.

[0236] The motor drive control unit 92 performs speed feedback control when it receives a drive command and a target rotational speed from the motion control unit 91. Specifically, the motor drive control unit 92 calculates the speed deviation, which is the difference between the target rotational speed and the actual rotational speed. The motor drive control unit 92 then calculates the duty cycle required to make the speed deviation zero (i.e., to make the actual rotational speed match the target rotational speed). It then outputs a drive control signal to each of the two target switches to turn on. The target switches are two of the first to sixth switches Q1 to Q6, corresponding to the rotational position. At least one of the drive control signals to the target switches is a pulse width modulated signal with the calculated duty cycle. Therefore, the higher the duty cycle, the greater the power supplied to the motor 20.

[0237] The display control unit 85 displays the rotation speed level input from the operation mode setting unit 87 on the first display screen 74. The display control unit 85 displays the actual number of reciprocations input from the reciprocation count calculation unit 79 on the set reciprocation count display screen 75. The display control unit 85 executes notification processing when it is notified that air lock has occurred. The notification processing notifies the user that air lock has occurred. The notification processing may be performed in any way. The notification processing may be performed in a way that allows the user to visually and / or audibly recognize that air lock has occurred. In the first embodiment, air lock is notified by flashing the second display screen 75A and the third display screen 75B. Alternatively, the display control unit 85 may notify air lock by displaying a preset number, symbol, character, etc. on the second display screen 75A and the third display screen 75B. The display control unit 85 is an example of a notification unit in the summary of the embodiment.

[0238] (2-1-6) Main Processing The main processing performed by the control circuit 80 (more specifically, the CPU 80A) to realize various functions in quantitative dispensing mode will be explained with reference to Figure 13. When the control circuit 80 is set to quantitative dispensing mode, it performs the main processing shown in Figure 13.

[0239] When the control circuit 80 starts the main process, it determines in S110 whether the trigger switch 8 is ON or OFF. If the trigger switch 8 is OFF, the process proceeds to S120. In S120, the control circuit 80 executes the stop-down process. Details of the stop-down process are shown in Figure 14.

[0240] When the control circuit 80 transitions to the stop processing, it stops the motor 20 in S210. Specifically, the motion control unit 91 stops outputting the drive command. In S220, the control circuit 80 determines whether the current round-trip count difference is zero. If the round-trip count difference is not zero, the process proceeds to S240. In this case, the current round-trip count difference is maintained. If the round-trip count difference is zero, the process proceeds to S230. An example of a case where the round-trip count difference is zero in S220 may include the case where the motor 20 is automatically stopped after the target number of round trips of the plunger 50 are completed, and the user then turns off the trigger 9. In S230, the control circuit 80 resets the actual number of round trips to an initial value (e.g., zero).

[0241] In S240, the control circuit 80 determines whether or not a change operation has been performed to modify the target number of round trips. The change operation includes turning on the second switch 72 or the third switch 73. If no change operation has been performed, the process proceeds to S270. If a change operation has been performed, the process proceeds to S250.

[0242] In S250, the control circuit 80 resets the actual number of round trips to its initial value. In S260, the control circuit 80 changes the target number of round trips according to the change operation. In S270, the control circuit 80 determines whether a speed change operation has been performed. The speed change operation includes turning on the first switch 71. If no speed change operation has been performed, the process proceeds to S290. If a speed change operation has been performed, the process proceeds to S280. In S280, the control circuit 80 changes the rotation speed level (i.e., changes the maximum rotation speed) in accordance with the speed change operation.

[0243] In S290, the control circuit 80 sets the air biting continuous state to "not detected". The control circuit 80 further sets (resets) the air biting continuous time to zero. After the processing of S290, this processing proceeds to S140 (FIG. 13).

[0244] When the trigger switch 8 is turned on in S110, this processing proceeds to S130. In S130, the control circuit 80 executes the operation processing. Details of the operation processing are as shown in FIG. 15 as follows.

[0245] When the control circuit 80 proceeds to the operation processing, in S310, it determines whether the air biting continuous state is set to "detected". If the air biting continuous state is not set to "detected", this processing proceeds to S320. In S320, the control circuit 80 determines whether the current reciprocation number difference is greater than 0. If the reciprocation number difference is 0, the control circuit 80 stops the drive of the motor 20 in S410 in the same manner as in S210. The fact that the reciprocation number difference is 0 corresponds to the execution of the discharge operation of the target reciprocation number. After S410, this processing proceeds to S420.

[0246] In S320, if the reciprocation number difference is greater than 0, this processing proceeds to S330. The fact that the reciprocation number difference is greater than 0 corresponds to the actual reciprocation number not yet reaching the target reciprocation number. In S330, the control circuit 80 drives the motor 20 at the target rotational speed according to the current rotational speed level. That is, the above-described speed feedback control is executed.

[0247] In S340, the control circuit 80 determines whether the plunger 50 has completed one reciprocation. In S350, the control circuit 80 executes the air biting detection processing. The air biting detection processing is a processing for detecting whether air biting has occurred. Details of the air biting detection processing are as shown in FIG. 16.

[0248] When the control circuit 80 proceeds to the air biting detection processing, in S510, it calculates the actual rotational speed of the motor 20 and calculates the motor acceleration based on the actual rotational speed. In S520, the control circuit 80 acquires the motor current value.

[0249] In S530, the control circuit 80 calculates the estimated torque using (i) the motor acceleration calculated in S510 and (ii) the motor current value obtained in S520. Specifically, the control circuit 80 calculates the load torque or load-inclusive torque based on equation (5) or equation (6) above. When the load torque is calculated using equation (5), the calculated load torque is obtained as the estimated torque. In other words, the load torque is directly calculated using equation (5).

[0250] When the load-inclusive torque is calculated using equation (6), the estimated torque is calculated indirectly with the mechanical loss torque superimposed on the estimated torque. As mentioned above, in this first embodiment, the mechanical loss torque is constant and identifiable (known), so if the load-inclusive torque is calculated, the load torque can be obtained. Therefore, calculating the load-inclusive torque using equation (6) is essentially equivalent to calculating the load torque. In other words, equation (6) can also be considered an arithmetic formula for calculating the load torque.

[0251] In S530, the control circuit 80 further updates the maximum torque based on the calculated estimated torque. The maximum torque is (i) reset each time the plunger 50 completes one cycle, and (ii) updated each time S530 is executed after the reset. Specifically, if the latest estimated torque calculated in this S530 is greater than the currently held maximum torque, the maximum torque is updated to the latest estimated torque. If the latest estimated torque calculated is less than or equal to the currently held maximum torque, no update is performed.

[0252] Furthermore, if load-included torque is calculated, the maximum value of the load-included torque may be retained as a substitute for the maximum load-included torque, which represents the maximum value of the load torque. In other words, if the latest load-included torque calculated this time is greater than the currently retained maximum load-included torque, the maximum load-included torque may be updated to that latest load-included torque. Retaining the maximum load-included torque means indirectly retaining the maximum torque. Therefore, the maximum Maintaining load-inclusive torque is essentially synonymous with maintaining maximum torque.

[0253] In S540, the control circuit 80 determines whether the plunger 50 has completed one reciprocal motion based on the determination result in S340. If the plunger 50 has not yet completed one reciprocal motion, the process proceeds to S550. In S550, the control circuit 80 maintains the current air entrapment detection state ("detected" or "not detected"). After processing in S550, the process proceeds to S360 (Figure 15).

[0254] In S540, if the plunger 50 completes one round trip, the process proceeds to S560. In S560, the control circuit 80 sets the first threshold. Specifically, as described above, the control circuit 80 sets the first threshold based on the target rotational speed, duty cycle, actual rotational speed, or equipment temperature.

[0255] In S570, the control circuit 80 determines whether the currently held maximum torque (i.e., the maximum estimated torque during the previous round trip period) is greater than the first threshold. If the maximum torque is greater than the first threshold, the process proceeds to S580. In this case, the control circuit 80 determines that no air lock has occurred. Therefore, in S580, the control circuit 80 sets the air lock detection state to "not detected". After processing in S580, the process proceeds to S600.

[0256] If the maximum torque is below the first threshold, the process proceeds to S590. In this case, the control circuit 80 determines that air has entered the system. Therefore, in S590, the control circuit 80 sets the air entry detection state to "detected". After processing in S590, the process proceeds to S600.

[0257] Furthermore, if the load-inclusive torque is calculated in S530 and the maximum load-inclusive torque is updated, the decision in S570 may be made based on the currently held maximum load-inclusive torque. Specifically, an alternative threshold may be set by adding the mechanical loss torque to the first threshold. Then, if the currently held maximum load-inclusive torque is greater than the alternative threshold, it may be determined that no air entrapment has occurred. Comparing the maximum load-inclusive torque with the alternative threshold in this way is equivalent to comparing the maximum torque with the first threshold. Alternatively, the maximum torque may be calculated by subtracting the mechanical loss torque from the currently held maximum load-inclusive torque. Then, the calculated maximum torque may be compared with the first threshold.

[0258] In S600, the control circuit 80 resets the currently held maximum torque. The control circuit 80 further resets the determination result in S340 that the plunger 50 has completed one reciprocation, and restarts the determination of whether or not the plunger 50 has completed one reciprocation. Therefore, when the plunger 50 completes one reciprocation from the timing of this restart, the determination of one reciprocation of the plunger 50 is made again in S340. After processing in S600, this process moves on to S360 (Figure 15).

[0259] In S360, the control circuit 80 determines whether the plunger 50 has completed one round trip based on the determination result in S340. If the plunger 50 has not completed one round trip, the process proceeds to S420. If the plunger 50 has completed one round trip, the process proceeds to S370.

[0260] In S370, the control circuit 80 determines whether the air lock detection state is set to "detected". If the air lock detection state is set to "detected", that is, if air lock has occurred, the process proceeds to S400. In S400, the control circuit 80 starts the notification process described above. That is, it notifies the user that air lock has occurred. After the processing in S400, the process proceeds to S420.

[0261] In S370, if the air lock detection status is not set to "detected," that is, if no air lock has occurred, the process proceeds to S380. In S380, the control circuit 80 increments the actual round trip count. That is, it adds "1" to the current actual round trip count. In S390, if the notification process is being executed, the control circuit 80 terminates that notification process. After the processing in S390, the process proceeds to S420.

[0262] Furthermore, if the air lock detection status in S370 is set to "Detected," the actual number of reciprocations is not incremented, and the current actual number of reciprocations is maintained. In other words, as long as air lock is detected, the actual number of reciprocations does not change even if the plunger 50 makes one reciprocation.

[0263] If the air lock condition is set to "detected" in S310, the process proceeds to S430. In S430, the control circuit 80 stops the motor 20 from running, similar to S210. After the process in S430, the process proceeds to S140 (Figure 13).

[0264] In S420, the control circuit 80 executes a continuation determination process. Details of the continuation determination process are shown in Figure 17. When the control circuit 80 moves to the continuation determination process, in S610 it determines whether the air lock detection state is set to "detected". If the air lock detection state is not set to "detected", that is, if no air lock has occurred, this process moves to S620.

[0265] In S620, the control circuit 80 resets the air-entry duration to zero. After processing in S620, the process proceeds to S140 (Figure 13). In S610, if the air lock detection state is set to "detected," that is, if air lock has occurred, the process proceeds to S630. In S630, the control circuit 80 accumulates the duration of the air lock. In other words, it accumulates (cumulatively) one of the aforementioned count values ​​used for measurement.

[0266] In S640, the control circuit 80 determines whether the duration of air lock is greater than or equal to a predetermined time (i.e., the count value is greater than or equal to a predetermined value). If the duration of air lock is less than the predetermined time, the process proceeds to S140 (Figure 13). If the duration of air lock is greater than or equal to the predetermined time, the process proceeds to S650.

[0267] In S650, the control circuit 80 sets the air lock-in state to "detected". In other words, it determines that the air lock-in has been occurring for a predetermined time or longer. After S650, this process moves on to S140 (Figure 13).

[0268] In S140, the control circuit 80 calculates (i.e., updates) the round-trip count difference. Specifically, it subtracts the current actual round-trip count from the current target round-trip count. Then, it updates the round-trip count difference to the result of that subtraction.

[0269] In S150, the control circuit 80 determines whether the current actual number of reciprocations is zero. If the actual number of reciprocations is not zero, the process proceeds to S160. In this case, the plunger 50 has already made at least one reciprocation in quantitative dispensing mode. Therefore, in S160, the control circuit 80 displays the current actual number of reciprocations on the set count display screen 75. This allows the user to recognize how far the grease has been dispensed. After processing in S160, the process proceeds to S110.

[0270] If the actual number of round trips is zero in S150, the process proceeds to S170. In this case, for example, it is possible that trigger 9 has not yet been manually operated, or that trigger 9 has been manually operated but the actual number of round trips has not yet reached one. Therefore, in S170, the control circuit 80 displays the target number of round trips on the set count display screen 75. The system can recognize the target number of round trips. After processing in S160, this process proceeds to S110.

[0271] Here, we will briefly explain the correspondence between the processes in Figures 13 to 17 and Figure 6. S110, S310, and S320 correspond to the processes performed by the operation control unit 91. S210, S330, S410, and S430 correspond to the processes performed by the operation control unit 91 and the motor drive control unit 92. S140, S220, S230, S250, and S380 correspond to the processes performed by the round-trip count calculation unit 79. S240 and S260 correspond to the processes performed by the round-trip count setting unit 83. S270 and S280 correspond to the processes performed by the operation mode setting unit 87. S290 and S420 correspond to the processes performed by the timing unit 88. S340 and S360 correspond to the processes performed by the round-trip determination unit 89. S350 corresponds to the processes performed by the air entrapment detection unit 90. S370 corresponds to the processes performed by the round-trip count calculation unit 79 and the display control unit 85. S150-S170, S390, and S400 correspond to processing by the display control unit 85.

[0272] [2-2. Second Embodiment] Another example of the air-entry detection process will be described as a second embodiment. The electric lubricant dispenser of this second embodiment is basically configured the same as the electric lubricant dispenser 1 of the first embodiment, except for the air-entry detection process. The configuration that differs from the first embodiment will be described below.

[0273] In this second embodiment, the air lock detection unit 90 detects the occurrence of air lock based on the amplitude of the load torque. As mentioned above, the load torque can fluctuate periodically during the operation of the pump 60. In other words, an amplitude of load torque occurs during the operation of the pump 60. This amplitude differs between the normal state and the air lock state (see estimated torque in Figures 10 and 11).

[0274] Therefore, the air lock detection unit 90 calculates the estimated torque in the same manner as in the first embodiment. Then, it detects the occurrence of air lock based on the amplitude of the estimated torque within a predetermined driving period. The amplitude of the estimated torque in an air lock state is smaller than the amplitude of the estimated torque in a normal state. Therefore, the air lock detection unit 90 determines that air lock has occurred when the maximum value of the amplitude of the estimated torque within a predetermined driving period is less than or equal to the second threshold. In other words, the first requirement described above includes the condition that the maximum value of the amplitude of the estimated torque within a predetermined driving period is less than or equal to the second threshold. To put it another way, the first requirement is met and it is determined that air lock has occurred when the maximum value of the amplitude of the estimated torque within a predetermined driving period is less than or equal to the second threshold. The maximum value of the amplitude within a predetermined driving period is the difference between the maximum and minimum values ​​of the estimated torque within a predetermined driving period.

[0275] The second threshold may be determined to be smaller than the expected amplitude range (e.g., its minimum value) under normal conditions and larger than the expected amplitude range (e.g., its maximum value) under air entrapment conditions. The second threshold may be determined in any way.

[0276] The second threshold value may be a constant value, but in this second embodiment, similar to the first threshold value in the first embodiment, it is variably set according to the operating state of the electric lubricant dispenser 1. Specifically, the second threshold may be set according to the target rotational speed. More specifically, the second threshold may be set so that, like the first threshold, the second threshold increases as the target rotational speed increases. For example, the vertical axis in Figure 12 may be interpreted as the second threshold.

[0277] Furthermore, the second threshold may be set according to various operating conditions such as actual rotational speed, duty cycle, or equipment temperature, similar to the first threshold. Specifically, the second threshold may be set according to the actual rotational speed in the same manner as the setting method according to the target rotational speed. For example, the horizontal axis in Figure 12 may be read as actual rotational speed and the vertical axis as the second threshold. Alternatively, the second threshold may be set according to the duty cycle in the same manner as the setting method for the first threshold according to the duty cycle. For example, the horizontal axis in Figure 12 may be read as duty cycle and the vertical axis as This can be interpreted as the second threshold. Alternatively, the second threshold can be set based on the equipment temperature in the same manner as the first threshold is set based on the equipment temperature.

[0278] To achieve this type of air lock detection, in this second embodiment, at S350 in Figure 15, the air lock detection process shown in Figure 18 is executed instead of the air lock detection process shown in Figure 16.

[0279] The air-entry detection process in Figure 18 differs from the air-entry detection process in Figure 16 in the following ways: (i) S531 is executed instead of S530, (ii) S561 is executed instead of S560, (iii) S571 is executed instead of S570, and (iv) S601 is executed instead of S600. Processes that are the same as those in the air-entry detection process in Figure 16 are denoted by the same reference numerals as in Figure 16, and their detailed explanations are omitted.

[0280] In S531, the control circuit 80 first calculates the estimated torque based on equation (5) or equation (6), similar to S530. Then, it updates the maximum or minimum torque based on the calculated estimated torque. Specifically, if the latest estimated torque calculated in S531 is greater than the currently held maximum torque, the maximum torque is updated to the latest estimated torque. If the latest estimated torque calculated in S531 is less than the currently held minimum torque, the minimum torque is updated to the latest estimated torque. If the latest estimated torque calculated is less than or equal to the currently held maximum torque and greater than or equal to the currently held minimum torque, no update is performed. The maximum and minimum torques can be (i) reset each time the plunger 50 completes one cycle, and (ii) updated each time S531 is executed after the reset.

[0281] Furthermore, when load-included torque is calculated, the maximum value of the load-included torque may be retained as a substitute maximum torque representing the maximum load torque, and the minimum value of the load-included torque may be retained as a substitute minimum torque representing the minimum load torque. In other words, if the latest load-included torque calculated is greater than the currently retained substitute maximum torque, the substitute maximum torque may be updated to the latest load-included torque. If the latest load-included torque calculated is less than the currently retained substitute minimum torque, the substitute minimum torque may be updated to the latest load-included torque. Retaining substitute maximum and substitute minimum torques means indirectly retaining maximum and minimum torques. Therefore, retaining substitute maximum and substitute minimum torques is substantially synonymous with retaining maximum and minimum torques.

[0282] In S561, the control circuit 80 sets a second threshold. Specifically, as mentioned above, the control circuit 80 sets a second threshold based on the target rotational speed, duty cycle, actual rotational speed, or equipment temperature.

[0283] In S571, the control circuit 80 determines whether the maximum amplitude of the estimated torque (i.e., the maximum value of the estimated torque amplitude during the previous cycle) is greater than the second threshold. The maximum amplitude is the difference between the currently held maximum torque and minimum torque. Each time the plunger 50 completes one cycle, S531 obtains the maximum and minimum torques for that cycle. The difference between these maximum and minimum torques is the maximum amplitude.

[0284] Note that the amplitude of the load-inclusive torque is equal to the amplitude of the load torque. Therefore, if the alternative maximum torque and alternative minimum torque are maintained, the difference between the alternative maximum torque and the alternative minimum torque may be calculated. The calculated difference is equal to the maximum amplitude of the estimated torque. Therefore, the decision in S571 may be made based on the calculated difference (i.e., the maximum amplitude).

[0285] If the maximum amplitude is greater than the second threshold in S571, the process proceeds to S580. In this case, the control circuit 80 determines that no air lock has occurred. If the maximum amplitude is less than or equal to the second threshold, the process proceeds to S590. In this case, the control circuit 80 determines that air lock has occurred.

[0286] In S601, the control circuit 80 resets the currently held maximum and minimum torques. Furthermore, similar to S600 in the first embodiment, the control circuit 80 resets the determination result in S340 that the plunger 50 has completed one reciprocation, and restarts the determination of whether or not the plunger 50 has completed one reciprocation.

[0287] [2-3. Third Embodiment] Another example of the air-entry detection process will be described as a third embodiment. The electric lubricant dispenser of this third embodiment is basically configured the same as the electric lubricant dispenser 1 of the first embodiment, except for the air-entry detection process. The configuration that differs from the first embodiment will be described below.

[0288] In this third embodiment, the air lock detection unit 90 detects the occurrence of air lock based on the differential value of the load torque. The load torque when the plunger 50 descends is smaller in the air lock state than in the normal state. In other words, in the normal state, the increase in load torque when the plunger 50 descends is large, whereas in the air lock state, the increase in load torque when the plunger 50 descends is small.

[0289] Therefore, as illustrated in Figures 19 and 20, the maximum value of the derivative of the estimated torque under air-entrained conditions (see Figure 19) is smaller than the maximum value of the derivative of the estimated torque under normal conditions (see Figure 20).

[0290] Therefore, the air lock detection unit 90 of this third embodiment determines that air lock has occurred when the maximum value of the differential value of the estimated torque within a predetermined driving period is less than or equal to the third threshold. In other words, the first requirement in this third embodiment includes the condition that the maximum value of the differential value of the estimated torque within a predetermined driving period is less than or equal to the third threshold.

[0291] The differential value may be calculated based on, for example, the time derivative. That is, the change in estimated torque per predetermined unit time may be calculated as the differential value. Alternatively, for example, the differential value may be calculated based on the rotation angle derivative. That is, the change in estimated torque while the motor 20 (more specifically the rotor 22) rotates by a predetermined unit rotation angle may be calculated as the differential value.

[0292] The third threshold may be determined to be smaller than the range of differential values ​​expected under normal conditions (e.g., its minimum value) and larger than the range of differential values ​​expected under air-trap conditions (e.g., its maximum value). The third threshold may be determined in any way.

[0293] The third threshold value may be a constant value, but in this third embodiment, similar to the first threshold value in the first embodiment, it is set variably according to the operating state of the electric lubricant dispenser 1. Specifically, the third threshold may be set according to the target rotational speed. More specifically, the third threshold may be set in the same manner as the first threshold, such that the third threshold increases as the target rotational speed increases. For example, the vertical axis in Figure 12 may be interpreted as the third threshold.

[0294] For example, the third threshold may be set according to various operating conditions such as actual rotational speed, duty cycle, or equipment temperature, similar to the first threshold. Specifically, the third threshold may be set according to the actual rotational speed in the same manner as the setting method according to the target rotational speed. For example, Alternatively, the horizontal axis in Figure 12 may be interpreted as the actual rotational speed and the vertical axis as the third threshold. Furthermore, the third threshold may be set according to the duty cycle in the same manner as the method for setting the first threshold according to the duty cycle. For example, the horizontal axis in Figure 12 may be interpreted as the duty cycle and the vertical axis as the third threshold. Also, the third threshold may be set based on the equipment temperature in the same manner as the method for setting the first threshold based on the equipment temperature.

[0295] To achieve this type of air lock detection, in this third embodiment, at S350 in Figure 15, the air lock detection process shown in Figure 21 is executed instead of the air lock detection process shown in Figure 16.

[0296] The air-entry detection process in Figure 21 differs from the air-entry detection process of the second embodiment in Figure 18 in the following ways: (i) S532 is executed instead of S531, (ii) S562 is executed instead of S561, (iii) S572 is executed instead of S571, and (iv) S602 is executed instead of S601. Processes that are the same as those in the air-entry detection process in Figure 18 are denoted by the same reference numerals as in Figure 18, and their detailed explanations are omitted.

[0297] In S532, the control circuit 80 first calculates the estimated torque based on equation (5) or equation (6), similar to S531. Furthermore, it calculates the derivative of the estimated torque. Then, it updates the maximum derivative based on the calculated derivative. Specifically, if the latest derivative calculated in S532 is greater than the currently held maximum derivative, the maximum derivative is updated to the latest derivative. The maximum derivative can be (i) reset each time the plunger 50 completes one cycle, and (ii) updated each time S532 is executed after the reset.

[0298] Note that fluctuations in load-included torque are equal to fluctuations in load torque. Therefore, when load-included torque is calculated in S532, the derivative of that load-included torque is calculated as the derivative of the load torque. Based on the calculated derivative, the maximum derivative is updated or retained.

[0299] In S562, the control circuit 80 sets a third threshold. Specifically, as described above, the control circuit 80 sets a third threshold based on the target rotational speed, duty cycle, actual rotational speed, or equipment temperature.

[0300] In S572, the control circuit 80 determines whether the currently held maximum derivative value (i.e., the maximum value of the derivative of the estimated torque during the previous round trip period) is greater than the third threshold. If the maximum derivative value is greater than the third threshold, the process proceeds to S580. In this case, the control circuit 80 determines that no air has been trapped. If the maximum derivative value is less than or equal to the third threshold, the process proceeds to S590. In this case, the control circuit 80 determines that air has been trapped.

[0301] In S602, the control circuit 80 resets the currently held maximum differential value. Furthermore, similar to S600 in the first embodiment, the control circuit 80 resets the determination result in S340 that the plunger 50 has completed one round trip, and restarts the determination of whether or not the plunger 50 has completed one round trip.

[0302] [2-4. Fourth Embodiment] Another example of the air entrapment detection process will be described as a fourth embodiment. The electric lubricant dispenser of this fourth embodiment is basically configured the same as the electric lubricant dispenser 1 of the first embodiment, except for the air entrapment detection process. The configuration that differs from the first embodiment will be described below.

[0303] In the first embodiment, the air lock detection unit 90 detects air lock based on the estimated torque while the motor is running. In contrast, the air-entry detection unit 90 of this fourth embodiment switches the detection method according to the operating state of the motor 20.

[0304] Specifically, during the acceleration and deceleration periods of the motor 20 (in other words, when the motor 20 is not in the steady state described above), the air entrapment detection unit 90 detects air entrapment based on the estimated torque, similar to any of the first to third embodiments.

[0305] On the other hand, in a steady state, the air lock detection unit 90 detects air lock based on the motor current value. The air lock detection unit 90 may detect air lock based on the motor current value in any way. For example, it can be determined that air lock has occurred if the maximum value of the amplitude of the motor current value within a predetermined driving period (hereinafter referred to as "maximum amplitude") is less than or equal to the first current threshold. Also, for example, it can be determined that air lock has occurred if the maximum value of the motor current value within a predetermined driving period is less than or equal to the second current threshold. Also, for example, it can be determined that air lock has occurred if the maximum value of the derivative of the motor current value within a predetermined driving period is less than or equal to the third current threshold.

[0306] A specific example of the air lock detection process of this fourth embodiment will be described with reference to Figures 22 and 23. In the air lock detection process shown in Figures 22 and 23, air lock is detected based on the maximum torque (i.e., the maximum value of the estimated torque) during the acceleration and deceleration periods, and air lock is detected based on the maximum amplitude of the motor current value in the steady state.

[0307] The air lock detection process shown in Figures 22 and 23 differs from the air lock detection process in Figure 16 in the following ways: (i) S525 is added between S520 and S530, S600 is deleted, and (ii) the processes S710 to S760 are added after the positive determination in S540. Processes identical to those in the air lock detection process in Figure 16 are denoted by the same reference numerals as in Figure 16, and their detailed explanations are omitted.

[0308] In S525, following S520, the control circuit 80 updates the maximum or minimum current value. Specifically, if the latest motor current value obtained in the preceding S520 is greater than the currently held maximum current value, the maximum current value is updated to that latest motor current value. If the latest motor current value obtained in the preceding S520 is less than the currently held minimum current value, the minimum current value is updated to that latest motor current value.

[0309] If it is determined in S540 that the plunger 50 has completed one cycle, the process proceeds to S710 (see Figure 23). In S710, the control circuit 80 determines whether the motor 20 is currently in an acceleration or deceleration phase. If it is in an acceleration or deceleration phase, the process proceeds to S560. Then, as in the first embodiment, it is determined whether or not air entrapment has occurred based on a comparison of the maximum torque and the first threshold.

[0310] If the process in S710 is neither an acceleration period nor a deceleration period, the process proceeds to S720. In S720, the control circuit 80 sets a first current threshold. The first current threshold may be a predetermined constant value, or it may be set variably according to the operating state of the electric lubricant dispenser 1.

[0311] In S730, the control circuit 80 determines whether the maximum amplitude of the motor current value (i.e., the maximum amplitude of the motor current value during the previous round trip period) is greater than the first current threshold. The maximum amplitude of the motor current value is the difference between the currently held maximum current value and the minimum current value.

[0312] If the maximum amplitude of the motor current value is greater than the first current threshold, this process proceeds to S740. In this case, the control circuit 80 determines that no air lock has occurred and sets the air lock detection status to "not detected". After processing in S740, this process proceeds to S760.

[0313] If, in S730, the maximum amplitude of the motor current is less than or equal to the first current threshold, the process proceeds to S750. In this case, the control circuit 80 determines that air lock has occurred and sets the air lock detection state to "detected". After processing in S750, the process proceeds to S760.

[0314] In S760, the control circuit 80 resets the currently held maximum current value, minimum current value, and maximum torque. Furthermore, similar to S600 in the first embodiment, the control circuit 80 resets the determination result of S340 that the plunger 50 has completed one reciprocation, and restarts the determination of whether or not the plunger 50 has completed one reciprocation. S760 is executed after S580 and after S590.

[0315] [2-5. Other Embodiments] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0316] (2-5-1) In the above embodiment, air entrapment was detected based on the load torque (specifically, the estimated torque), the amplitude of the load torque, or the derivative of the load torque. However, air entrapment may be detected based on the load torque or any physical quantity including the load torque.

[0317] (2-5-2) The operating conditions referenced in setting the first threshold are not limited to the operating conditions exemplified in each of the above embodiments (target rotational speed, duty cycle, actual rotational speed, or equipment temperature). The first threshold may be set based on any operating condition in the electric lubricant dispenser 1. The operating condition may be any that affects the load torque, that is, any condition in which the load torque may change in response to a change in the operating condition.

[0318] For example, the operating state may be the battery voltage. In other words, the first threshold may be set according to the magnitude of the battery voltage. Even if the duty cycle is constant, if the battery voltage decreases, the power supplied to the motor 20 will also decrease, and the load torque will decrease as a result. For this reason, the first threshold may be set according to the magnitude of the battery voltage. Specifically, the first threshold may be set so that it decreases as the battery voltage decreases. To achieve this, the electric lubricant dispenser 1 may be equipped with a voltage detector that detects the battery voltage. The voltage detector may be configured to (i) receive the battery voltage and (ii) output a voltage detection signal to the control circuit 80 according to the magnitude of that voltage. The control circuit 80 may (i) acquire the magnitude of the battery voltage based on the voltage detection signal from the voltage detector and (ii) set the first threshold based on the acquired magnitude.

[0319] The second and third thresholds may also be set variably based on various other operating conditions. (2-5-3) In the first embodiment, the first threshold may be set based on the average value of a numerical value indicating the operating state (hereinafter referred to as "state quantity"). The average value is, in other words, a smoothed value. Examples of state quantities include target rotational speed, duty cycle, actual rotational speed, or equipment temperature. The average value of the state quantity may be calculated by any method. For example, an interval average or moving average of the state quantity may be calculated. In this case, the first threshold may be set according to the calculated interval average or moving average. The intervals to be calculated for the interval average and moving average may be determined in any way. The calculation interval may be, for example, the predetermined drive period described above (i.e., the period during which the plunger 50 completes one round trip).

[0320] Alternatively, a low-pass filter may be provided to which a state variable is input. The filter removes components above a predetermined frequency from the state quantities input in a time series and outputs the state quantities from which those components have been removed. The first threshold may be set according to the output value of the low-pass filter. The low-pass filter may be implemented by the CPU 80A executing a program for the low-pass filter.

[0321] The second threshold in the second embodiment and the third threshold in the third embodiment may also be set based on averaged state variables, similar to the first threshold. (2-5-4) In the above embodiment, examples of predetermined processes to be performed when air entrapment is detected include notification processing and temporary suspension of the accumulation of the actual number of round trips. However, if air entrapment is detected, other predetermined processes may be performed in addition to or instead of these processes.

[0322] (2-5-5) In the above embodiment, the reciprocating determination unit 89 determined one reciprocating motion of the plunger 50 based on the first to third rotation signals. However, one reciprocating motion of the plunger 50 can be determined by any method. For example, a sensor capable of detecting the rotation of the crankshaft 46 may be provided near the crankshaft 46. One reciprocating motion of the plunger 50 may be determined based on the detection result from that sensor. Alternatively, for example, a sensor that detects the position of the plunger 50 or slider 48 may be provided near the plunger 50 or slider 48. One reciprocating motion of the plunger 50 may be determined based on the detection result from that sensor.

[0323] (2-5-6) The technology of the present disclosure is applicable to all types of reciprocating pumps. For example, the present disclosure is applicable to diaphragm pumps. Furthermore, it is applicable not only to reciprocating pumps but to all types of pumps capable of discharging lubricants.

[0324] (2-5-7) The electric lubricant dispenser 1 may be configured to dispense lubricants other than grease. These lubricants may be, for example, semi-solid or liquid (e.g., lubricating oil).

[0325] (2-5-8) The rotation speed level, operating mode, and target number of reciprocations may be set in a manner different from that of the above embodiment. For example, a user interface (e.g., a button, dial, lever, touch panel, etc.) of a different form than the second and third switches 72 and 73 of the above embodiment may be provided for setting the operating mode. The operating mode may be switched in response to the operation of the user interface. The same applies to the target number of reciprocations. The rotation speed level may also be switched in response to the operation of a user interface (e.g., a button, dial, lever, touch panel, etc.) of a different form than the first switch 71 of the above embodiment.

[0326] (2-5-9) In the above embodiment, the rotational state of the motor 20 (i.e., rotational position and actual rotational speed) was obtained using the first to third rotational position sensors 28A to 28C. However, the rotational state may be obtained by other means. For example, so-called sensorless control may be employed in the electric lubricant dispenser 1. That is, the rotational state of the motor may be obtained based on the induced voltage generated in each of the three coils 24 of the motor 20.

[0327] [2-6. Supplementary Information] Multiple functions achieved by one component in the above embodiment may be achieved by multiple components, and one function achieved by one component may be achieved by multiple components. Also, multiple functions achieved by multiple components may be achieved by one component, and one function achieved by multiple components may be achieved by one component. Furthermore, some parts of the configuration of the above embodiment may be omitted. Also, at least some parts of the configuration of one embodiment may be added to or replaced with the configuration of another embodiment. [Explanation of Symbols]

[0328] 1...Electric lubricant dispenser, 8...Trigger switch, 9...Trigger, 15...Battery pack, 20...Motor, 28A~28C...1st~3rd rotational position sensors, 48...Slider, 50...Plunger, 60...Pump, 63...Chamber, 66A...Discharge port, 70...Operation panel, 80...Control circuit, 80A...CPU, 80B...Semiconductor memory, 82...Drive circuit.

Claims

1. Motor and, A pump driven by the aforementioned motor and configured to discharge lubricant, A drive circuit configured to drive the motor, A control circuit, The drive circuit is controlled to rotate the motor, During the operation of the motor, a predetermined process is performed based on the fact that the load torque, which is the torque generated by the load received from the pump, among the torque applied to the motor from the outside, satisfies a first requirement indicating that gas is mixed into the pump. A control circuit configured as follows, An electric lubricant dispenser equipped with the following features.

2. An electric lubricant dispenser according to claim 1, The first requirement includes the condition that the maximum value of the load torque within a predetermined driving period is less than or equal to a first threshold, Electric lubricant dispenser.

3. An electric lubricant dispenser according to claim 1 or claim 2, The first requirement includes the condition that the maximum value of the amplitude of the load torque within a predetermined driving period is less than or equal to a second threshold. Electric lubricant dispenser.

4. An electric lubricant dispenser according to any one of claims 1 to 3, The first requirement includes the condition that the maximum value of the differential of the load torque within a predetermined driving period is less than or equal to a third threshold. Electric lubricant dispenser.

5. An electric lubricant dispenser according to claim 2, The control circuit is configured to change the first threshold value according to the operating state of the electric lubricant dispenser. Electric lubricant dispenser.

6. An electric lubricant dispenser according to claim 3, The control circuit is configured to change the second threshold value according to the operating state of the electric lubricant dispenser. Electric lubricant dispenser.

7. An electric lubricant dispenser according to claim 4, The control circuit is configured to change the third threshold value according to the operating state of the electric lubricant dispenser. Electric lubricant dispenser.

8. An electric lubricant dispenser according to any one of claims 5 to 7, The control circuit is configured to (i) set a target rotational speed which is a target value for the rotational speed of the motor, and (ii) control the drive circuit so that the rotational speed of the motor matches the target rotational speed. The aforementioned operating state includes the aforementioned target rotational speed, Electric lubricant dispenser.

9. An electric lubricant dispenser according to any one of claims 5 to 7, The control circuit is configured to control the drive circuit by outputting a pulse-width modulated signal having a duty cycle to the drive circuit. The drive circuit is configured to receive the pulse width modulated signal and drive the motor according to the received pulse width modulated signal. The aforementioned operating state includes the duty cycle, Electric lubricant dispenser.

10. An electric lubricant dispenser according to any one of claims 5 to 7, The aforementioned operating state includes the actual rotational speed of the motor. Electric lubricant dispenser.

11. An electric lubricant dispenser according to any one of claims 5 to 7, The control circuit is configured to acquire the temperature of the electric lubricant dispenser, The aforementioned operating state includes the temperature, Electric lubricant dispenser.

12. An electric lubricant dispenser according to any one of claims 1 to 11, The drive circuit is configured to supply current to the motor and rotate the motor, The aforementioned control circuit is Based on the magnitude of the current supplied from the drive circuit to the motor and the acceleration of the motor, the load torque, or the load-inclusive torque which includes the load torque and fluctuates approximately the same as the load torque, is calculated. Based on the fact that the calculated load torque, or the load torque included in the calculated load-inclusive torque, satisfies the first requirement, the predetermined process is performed. An electric lubricant dispenser configured in such a way.

13. An electric lubricant dispenser according to any one of claims 1 to 12, The pump is equipped with a notification unit configured to notify information indicating that the gas is mixed in with the pump, The predetermined process includes broadcasting the information via the notification unit. Electric lubricant dispenser.

14. An electric lubricant dispenser according to any one of claims 1 to 13, The pump is configured to repeatedly perform a predetermined discharge operation for discharging the lubricant, The aforementioned control circuit is While the motor is running, each time the pump performs the predetermined discharge operation, the actual number of discharges, which is the number of times the predetermined discharge operation has been performed, is accumulated. The motor is stopped based on the fact that the actual number of discharges has reached the target number of discharges. It is configured in such a way, The predetermined process includes temporarily suspending the accumulation of the actual number of discharges, Electric lubricant dispenser.

15. An electric lubricant dispenser according to claim 14, The control circuit is configured to temporarily stop accumulating the actual number of discharges, and then resume accumulating the actual number of discharges based on the fact that the load torque no longer satisfies the first requirement. Electric lubricant dispenser.

16. An electric lubricant dispenser according to any one of claims 1 to 15, The aforementioned pump, A chamber configured to contain the aforementioned lubricant, A discharge port communicating with the aforementioned chamber, (i) A plunger located within the chamber, and (ii) configured to reciprocate within the chamber by the motor to discharge the lubricant within the chamber from the discharge port, It is equipped with Electric lubricant dispenser.

17. An electric lubricant dispenser according to any one of claims 2 to 11, The aforementioned pump, A chamber configured to contain the aforementioned lubricant, A discharge port communicating with the aforementioned chamber, (i) A plunger located within the chamber, and (ii) configured to reciprocate within the chamber by the motor to discharge the lubricant within the chamber from the discharge port, Equipped with, The predetermined driving period includes the period during which the plunger makes one round trip within the chamber. Electric lubricant dispenser.

18. An electric lubricant dispenser according to claim 14 or claim 15, The aforementioned pump, A chamber configured to contain the aforementioned lubricant, A discharge port communicating with the aforementioned chamber, (i) A plunger located within the chamber, and (ii) configured to reciprocate within the chamber by the motor to discharge the lubricant within the chamber from the discharge port, Equipped with, The predetermined discharge operation includes the plunger making one round trip within the chamber. Electric lubricant dispenser.

19. An electric lubricant dispenser according to any one of claims 1 to 18, The control circuit is configured to stop the motor when the load torque has remained in a state that satisfies the first requirement for a predetermined period of time while the motor is being driven. Electric lubricant dispenser.

20. An electric lubricant dispenser according to any one of claims 1 to 19, The control circuit is configured to detect, in response to the first requirement being met while the motor is being driven, that the gas is mixed into the pump and / or that the pump is about to discharge the gas. Electric lubricant dispenser.

21. An electric lubricant dispenser according to any one of claims 1 to 20, The control circuit is configured to perform the predetermined processing based on the fact that the load torque during the period when the motor is accelerating or decelerating satisfies the first requirement. Electric lubricant dispenser.

22. An electric lubricant dispenser according to any one of claims 1 to 20, The drive circuit is configured to supply current to the motor and rotate the motor, The aforementioned control circuit is During the gear shift period in which the motor is accelerating or decelerating, the predetermined processing is performed based on the fact that the load torque during the gear shift period satisfies the first requirement. During the constant-speed period when the motor is rotating at a constant speed, the predetermined process is performed based on the fact that the magnitude of the current supplied to the motor satisfies the second requirement indicating that gas is mixed into the pump. It is structured in such a way. Electric lubricant dispenser.

23. A method for dispensing lubricant from an electric lubricant dispenser, The pump of the electric lubricant dispenser, which is configured to discharge the lubricant, is driven by the motor of the electric lubricant dispenser. During the operation of the motor, the load torque, which is the torque generated by the load received from the pump, among the torque applied to the motor from the outside, satisfies the requirement that gas is mixed into the pump, and based on this, the electric lubricant dispenser performs a predetermined process. A method that includes [the following features].

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