Grease discharge device

Abstract

To provide a grease discharge device capable of accurately detecting a discharge amount of grease from a discharge port due to reciprocating movement of a plunger.SOLUTION: A grease discharge device comprises: a pump that comprises a plunger that is reciprocated by rotation of a motor, and discharges grease by the reciprocating movement of the plunger; a drive unit that drives the motor to reciprocate the plunger; and a control unit that drives the motor at a predetermined rotational speed via the drive unit to reciprocate the plunger and measure the number of times the plunger reciprocates, and stops driving the motor when the measured number of reciprocations reaches a setting value set in advance. The control unit reduces a rotational speed of the motor according to the difference between the measured number of reciprocations and the setting value.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a grease dispensing device such as a grease gun. [Background technology]

[0002] The grease discharge device described in Patent Document 1 includes a pump that includes a plunger that is reciprocated by the rotation of a motor, and is configured to discharge grease supplied from a tank from a discharge port by the reciprocating movement of the plunger. Patent Document 1 also describes that when the motor is driven to discharge grease from the discharge port, the number of reciprocating movements of the plunger is measured, and when the number of reciprocating movements reaches a set value, the drive of the motor is stopped.

[0003] In other words, the amount of grease discharged from the discharge port is determined by the volume of the cylinder in which the plunger reciprocates in the pump and the number of reciprocations. For this reason, the grease discharge device described in Patent Document 1 monitors the amount of grease discharged by measuring the number of reciprocations of the plunger in the pump, and when the number of reciprocations reaches a set number, it determines that the desired amount of grease has been discharged from the discharge port and stops driving the motor. Therefore, according to the device described in Patent Document 1, the amount of grease discharged from the discharge port can be controlled to the desired amount. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US8528782B2 Summary of the Invention [Problem to be solved by the invention]

[0005] In a grease dispensing device, in order to efficiently dispense grease, the speed at which grease is dispensed from the nozzle (in other words, the amount of grease dispensed per unit time) can be increased by increasing the rotational speed of the motor when dispensing grease.

[0006] However, if the motor rotates at high speed when dispensing grease, the motor rotation cannot be stopped quickly even if the brake is applied when stopping the motor drive, and it takes time for the motor rotation to stop. Furthermore, since the plunger reciprocates due to the rotation of the motor from when the motor drive is stopped until the motor rotation stops, an excess of grease is dispensed, and the amount of grease dispensed cannot be controlled to the desired amount.

[0007] One aspect of the present disclosure aims to provide a grease dispensing device that enables the rotation of a motor to be quickly stopped when the amount of grease dispensed reaches a desired amount, even if the motor rotation speed during grease dispensing is set high. [Means for solving the problem]

[0008] A grease dispensing device according to one aspect of the present disclosure includes a motor, a pump, a drive unit, and a control unit. The pump includes a plunger that is reciprocated by the rotation of the motor, and the reciprocating movement of the plunger causes the grease supplied from the tank to be discharged from the discharge port. The drive unit drives the motor to reciprocate the plunger.

[0009] When the control unit receives a grease discharge command from the outside, the control unit drives the motor at a predetermined rotation speed via the drive unit to reciprocate the plunger, measures the number of reciprocations of the plunger, and stops driving the motor when the measured value of the number of reciprocations reaches a preset value. After driving the motor at the predetermined rotation speed, the control unit reduces the rotation speed of the motor in accordance with the difference between the measured value of the number of reciprocations and the set value.

[0010] Therefore, according to the grease dispensing device disclosed herein, when a grease dispensing command is input to the control unit, the motor is driven at a predetermined rotational speed and the plunger is caused to reciprocate within the pump, but the rotational speed of the motor then decreases in accordance with the difference between the measured number of reciprocations and the set value.

[0011] Therefore, when the measured number of times the plunger has reciprocated reaches the set value and the motor is stopped, the motor will be rotating at a speed lower than the specified rotational speed, and the time until the motor stops rotating after the motor is stopped can be shortened.

[0012] Therefore, it is possible to reduce the amount of grease discharged from the discharge port after the motor stops driving, and to control the amount of grease discharged to a desired amount. Also, since it is not necessary to set the predetermined rotation speed of the motor low in order to reduce the amount of grease discharged from the discharge port after the motor stops driving, the grease discharge operation can be carried out efficiently. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view illustrating an external appearance of a grease discharging device according to a first embodiment. [Diagram 2] 2 is a central vertical cross-sectional view of the grease discharging device shown in FIG. 1. [Diagram 3] 2 is a plan view showing an operation panel of the grease discharging device shown in FIG. 1. [Figure 4] 2 is an electric circuit diagram showing the overall configuration of a motor drive system in the grease dispensing device. FIG. [Diagram 5] 5 is a functional block diagram illustrating a functional configuration of a control circuit shown in FIG. 4. [Figure 6] 4 is a time chart illustrating a problem in the conventional technique for controlling the rotation speed of a motor to a constant speed. [Figure 7] 4 is a time chart showing changes in the rotation speed of the motor in the first embodiment. [Figure 8] 4 is a flowchart showing a control process executed by a control circuit of the first embodiment. [Figure 9] 4 is a flowchart showing motor drive control according to the first embodiment. [Figure 10] 5 is a flowchart illustrating a first modified example of the motor drive control of the first embodiment. [Figure 11]6 is a time chart showing changes in the rotation speed of a motor in a first modified example of the first embodiment. [Figure 12] 6 is a flowchart illustrating a second modified example of the motor drive control of the first embodiment. [Figure 13] 10 is a flowchart illustrating a third modified example of the motor drive control of the first embodiment. [Figure 14] 13 is a time chart showing changes in rotation speed of a motor in a third modified example of the first embodiment. [Figure 15] 13 is a flowchart showing a control process of a fourth modified example of the first embodiment. [Figure 16] FIG. 11 is a functional block diagram illustrating a functional configuration of a control circuit according to a second embodiment. [Figure 17] 10 is a flowchart showing a control process executed by a control circuit according to a second embodiment. [Figure 18] 10 is a flowchart showing a motor drive control according to a second embodiment. [Figure 19] 10 is a flowchart illustrating a first modified example of the motor drive control according to the second embodiment. [Figure 20] 10 is a flowchart illustrating a second modified example of the motor drive control according to the second embodiment. [Figure 21] 13 is a flowchart illustrating a third modified example of the motor drive control according to the second embodiment. [Figure 22] 13 is a flowchart showing a control process of a fourth modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1. Overview of the embodiment An embodiment may provide a grease dispensing device having at least one of the following features 1 to 5.

[0015] Feature 1: Motor. Feature 2: A pump comprising a plunger that is reciprocated by rotation of the motor, and configured so that the reciprocating motion of the plunger causes grease supplied from a tank to be discharged from a discharge port.

[0016] Feature 3: A drive unit configured to drive the motor to reciprocate the plunger. Feature 4: A control unit configured to, upon receiving a command to dispense the grease from the outside, drive the motor at a predetermined rotational speed via the drive unit to reciprocate the plunger, measure the number of reciprocations of the plunger, and stop driving the motor when the measured value of the number of reciprocations reaches a preset value.

[0017] Feature 5: The control unit is configured to drive the motor at the predetermined rotation speed, and then reduce the rotation speed of the motor in accordance with a difference between the measured value of the number of reciprocations and the set value.

[0018] In a grease discharge device having at least features 1 to 5, when a grease discharge command is input to the control unit, the motor is driven at a predetermined rotational speed to cause the plunger to reciprocate within the pump, and then the rotational speed of the motor is reduced in accordance with the difference between the measured number of reciprocations and a set value.

[0019] Therefore, when the measured number of times the plunger has reciprocated reaches the set value and the motor is stopped, the motor will be rotating at a speed lower than the specified rotational speed, and the time until the motor stops rotating after the motor is stopped can be shortened.

[0020] Therefore, it is possible to reduce the amount of grease discharged from the discharge port after the motor stops driving, and to control the amount of grease discharged to a desired amount. Also, since it is not necessary to set the predetermined rotation speed of the motor low in order to reduce the amount of grease discharged from the discharge port after the motor stops driving, the grease discharge operation can be carried out efficiently.

[0021] An embodiment may include the following feature 6 in addition to or instead of at least one of the features 1 to 5 above. Feature 6: The control unit is configured to reduce the rotation speed of the motor continuously or stepwise from the predetermined rotation speed so that the rotation speed of the motor decreases as the difference between the measured value of the number of reciprocations and the set value decreases.

[0022] In a grease discharge device having at least features 1 to 6, when the motor is driven at a predetermined rotational speed and the plunger reciprocates within the pump, the rotational speed of the motor is then reduced continuously or in stages depending on the difference between the measured number of reciprocations and a set value.

[0023] Therefore, when the measured value of the number of reciprocations of the plunger reaches the set value and the driving of the motor is stopped, the rotation speed of the motor is sufficiently low so that the rotation of the motor can be stopped more quickly. Therefore, the amount of grease discharged from the grease discharge device can be controlled to the desired amount with more precision.

[0024] In addition, even if the predetermined rotation speed for increasing the rotation speed of the motor after the motor starts to drive is set to a higher rotation speed, the amount of grease dispensed can be controlled to a desired amount. Therefore, by setting the predetermined rotation speed to a higher rotation speed, the grease dispense operation can be carried out more efficiently.

[0025] An embodiment may include the following feature 7 in addition to or instead of at least one of the features 1 to 5 above. Feature 7: The control unit is configured to measure the number of rotations of the motor as a parameter representing the number of reciprocating movements of the plunger, and after driving the motor at the predetermined rotation speed, reduce the rotation speed of the motor in accordance with a difference between the measured value of the number of rotations and a rotation speed set value corresponding to the set value, and stop driving of the motor when the measured value of the number of rotations reaches the rotation speed set value.

[0026] In the grease dispensing device having at least the above features 1 to 5 and 7, the control unit measures the number of revolutions of the motor as a parameter representing the number of reciprocations of the plunger. This is because the number of reciprocations of the plunger is proportional to the number of revolutions of the motor, and the control unit obtains the number of reciprocations of the plunger by measuring the number of revolutions of the motor.

[0027] The control unit then drives the motor at a predetermined rotational speed to reciprocate the plunger, and thereafter reduces the motor rotational speed in accordance with the difference between the measured value of the motor's rotation count and the set value of the rotation count, and stops driving the motor when the measured value of the rotation count reaches the set value of the rotation count.

[0028] Therefore, in this grease discharge device, when the motor is stopped, the motor rotates at a rotational speed lower than the predetermined rotational speed, and the time until the motor stops rotating after the motor is stopped can be shortened.

[0029] Therefore, it is possible to reduce the amount of grease discharged from the discharge port after the motor stops driving, and to control the amount of grease discharged to a desired amount. Also, since it is not necessary to set the predetermined rotation speed of the motor low in order to reduce the amount of grease discharged from the discharge port after the motor stops driving, the grease discharge operation can be carried out efficiently.

[0030] An embodiment may include the following feature 8 in addition to or instead of at least one of the features 1 to 5 and 7 above. Feature 8: The control unit is configured to reduce the rotation speed of the motor continuously or stepwise from the predetermined rotation speed so that the rotation speed of the motor decreases as the difference between the measured rotation count and the set rotation count value decreases.

[0031] In a grease discharge device having at least features 1 to 5, 7 and 8, when the motor is driven at a predetermined rotational speed and the plunger is reciprocated, the rotational speed of the motor is then reduced continuously or stepwise depending on the difference between the measured rotation speed and the set rotation speed.

[0032] Therefore, when the measured value of the number of reciprocations of the plunger reaches the set value and the driving of the motor is stopped, the rotation speed of the motor is sufficiently low so that the rotation of the motor can be stopped more quickly. Therefore, the amount of grease discharged from the grease discharge device can be controlled to the desired amount with more precision.

[0033] In addition, even if the predetermined rotation speed for increasing the rotation speed of the motor after the motor starts to drive is set to a higher rotation speed, the amount of grease dispensed can be controlled to a desired amount. Therefore, by setting the predetermined rotation speed to a higher rotation speed, the grease dispense operation can be carried out more efficiently.

[0034] An embodiment may include at least one of the following features 9 to 11 in addition to or instead of at least one of the features 1 to 8 above. Feature 9: An operation unit configured to input grease dispensing commands via external operation.

[0035] Feature 10: When the input of the discharge command from the operation unit is stopped while the motor is being driven, the control unit is configured to stop driving the motor and clear the measurement value.

[0036] Feature 11: The control unit is configured to stop driving the motor and hold the measurement value when the input of the ejection command from the operation unit is stopped while driving the motor, and to resume driving the motor and measuring the measurement value based on the measurement value when the input of the ejection command from the trigger is resumed.

[0037] In the grease dispensing device having at least the features 1 to 5, 9 and 10, when the input of the dispensing command from the operation unit is stopped while the motor is being driven, the control unit stops driving the motor and clears the measurement value. Therefore, when the next dispensing command is input from the operation unit, the control unit drives the motor at a predetermined rotation speed to perform the dispensing operation of grease from the discharge port from the beginning.

[0038] In a grease dispensing device having at least features 1 to 5, 9, and 11, when the input of a dispensing command from the operation unit is stopped while the motor is being driven, the control unit stops driving the motor and holds the measurement value. Then, when the input of the dispensing command from the operation unit is resumed, the control unit resumes driving the motor and measuring the measurement value based on the measurement value held when the motor was stopped.

[0039] Therefore, even if the user stops inputting a discharge command by operating the operation unit while grease is being discharged from the grease dispensing device, the user can resume dispensing of grease from the grease dispensing device by subsequently operating the operation unit to input a discharge command. Then, when the amount of grease dispensed from the grease dispensing device reaches a desired amount, the drive of the motor (in other words, the dispensing of grease) can be automatically stopped.

[0040] 2. Specific Exemplary Embodiments Certain exemplary embodiments of the present disclosure are described below in conjunction with the drawings. 2-1. First embodiment As shown in FIGS. 1 and 2, the grease dispensing device 1 of this embodiment is a so-called grease gun configured to dispense grease when a user pulls a trigger 9 serving as an operating unit, and has a housing 2.

[0041] The housing 2 is constructed by assembling left and right housing halves 2a, 2b with a number of screws 3, 3.... A cylindrical motor housing section 4 is formed in the front-rear direction in the vertical center of the housing 2. A grip section 5 is formed in the front-rear direction at the top of the housing 2. A front joint section 6 is formed on the front side of the motor housing section 4. The front end of the grip section 5, which is bent downward, is joined to the front joint section 6. The rear side of the motor housing section 4 forms a rear joint section 7 that rises upward. The rear end of the grip section 5 is joined to the rear joint section 7 to form a loop.

[0042] A trigger switch 8 is housed within the grip portion 5. The trigger switch 8 is for inputting a command to dispense grease, and is connected to a trigger 9 that protrudes downward. A light 10 using an LED is provided on the front surface of the grip portion 5. An operation panel 70 is provided on the front upper surface of the grip portion 5 for turning the light 10 on and off and setting the amount of grease dispensed. This operation panel 70 will be described in detail later.

[0043] A lock-on button 12 that can maintain the retracted state of the trigger 9 is provided on the grip portion 5 in front of the trigger 9. A lock-off button 13 that restricts the pulling operation of the trigger 9 is provided below the lock-on button 12 and in front of the trigger 9.

[0044] A battery holding section 14 is formed on the rear side of the rear coupling section 7. A battery pack (e.g., rated voltage 36V) 15 can be slid from above onto the rear side of the battery holding section 14. A terminal block 16 to which the mounted battery pack 15 is electrically connected is provided in the vertical direction within the battery holding section 14.

[0045] A controller 17 is provided vertically inside the battery holding portion 14 in front of the terminal block 16. The controller 17 includes a control circuit board 18 on which electronic components constituting a control circuit 80, such as a microcomputer, are mounted. In response to the user's operation of the trigger 9 or an operation panel 70, the controller 17 controls the operation of the light 10 and a motor 20, which will be described later, and causes a display circuit 72 of the operation panel 70 to display various information.

[0046] A motor 20 is accommodated within the motor housing portion 4. The motor 20 is an inner rotor type brushless motor having a stator 21 and a rotor 22 positioned inside the stator 21.

[0047] The stator 21 has a plurality of (six in this example) coils 24, 24 wound around insulators 23A, 23B provided on the front and rear end faces. The rear insulator 23B is provided with terminals (not shown) to which wires forming the coils 24 are fused, and with a short-circuit member 25.

[0048] The short-circuit member 25 is formed by insert molding three short-circuit metal fittings 26, 26... to which three-phase power lines 27, 27... are respectively connected. By connecting each short-circuit metal fitting 26 to each terminal, each coil 24 is three-phase connected. A sensor circuit board 28 is provided between the insulator 23B and the short-circuit member 25.

[0049] Sensor circuit board 28 is equipped with rotation detection elements (e.g., three Hall elements 28A-28C) for detecting the rotational position of rotor 22, and is connected to a plurality of signal lines 29, 29.... Power line 27 and signal line 29 are drawn out to the battery holding unit 14 side and connected to control circuit board 18 of controller 17.

[0050] The rotor 22 has a rotating shaft 30 at its axis. A plurality of permanent magnets 31, 31... are embedded around the rotating shaft 30. A fan 32 is attached to the front of the rotating shaft 30 in an orthogonal manner.

[0051] A plurality of air intake ports 33, 33... are formed on the left and right side surfaces of the rear coupling portion 7. The air intake ports 33 draw in outside air by the rotation of the fan 32. A plurality of exhaust ports 34, 34... are formed on the left and right side surfaces of the motor housing portion 4. The exhaust ports 34 are located radially outward and in front of the fan 32, and discharge the air drawn into the motor housing portion 4 to the outside.

[0052] A bearing 35 for supporting the rear end of the rotating shaft 30 is provided behind the short-circuit member 25 and within the rear joint 7 . A gear housing 40 is provided in front of the motor 20. The gear housing 40 is cylindrical, and a bracket plate 41 is attached to the rear end opening. The front end of the rotating shaft 30 penetrates the bracket plate 41 and protrudes into the gear housing 40. The bracket plate 41 holds a bearing 42 that supports the rotating shaft 30.

[0053] A reduction gear mechanism 43 is housed within the gear housing 40. The reduction gear mechanism 43 utilizes planetary gears to reduce the rotation of the rotating shaft 30 in three stages and outputs the rotation to a spindle 44 provided at the front end. A crank housing 45 extending in the vertical direction is provided at the front side of the gear housing 40. The spindle 44 protrudes from the gear housing 40 into the crank housing 45.

[0054] A crank disk 46 is provided integrally with the front end of the spindle 44 inside the crank housing 45. The crank disk 46 is provided with an eccentric pin 47 that protrudes forward. A slider 48 having a long hole 49 in the left-right direction is provided in front of the crank disk 46. The slider 48 is supported within the crank housing 45 so as to be able to move up and down, and the eccentric pin 47 is inserted into the long hole 49. The upper end of a rod-shaped plunger 50 that extends in the vertical direction is connected to the center of the lower end of the slider 48.

[0055] Therefore, when the crank plate 46 rotates together with the spindle 44, the eccentric pin 47 performs eccentric motion. Then, the slider 48 moves up and down due to the vertical stroke of the eccentric pin 47, and the plunger 50 moves up and down integrally therewith.

[0056] A cylindrical front holder 51 is formed at the lower part of the crank housing 45. A rear holder 52 that protrudes downward is provided behind the front holder 51 at the lower part of the motor housing portion 4. The rear holder 52 has front and rear legs 53, 53.

[0057] A tank 54 is supported by the front holder 51 and the rear holder 52. The tank 54 has an open front end and passes through the rear holder 52 from the rear, and the front end is screwed into the rear surface of the front holder 51. In this state, the tank 54 is connected to the front holder 51 in a position extending in the front-rear direction below the motor housing portion 4.

[0058] A rod 55 with a piston 56 at its front end is housed in the tank 54 so as to be movable in the front-rear direction. The rear end of the rod 55 protrudes from the rear end of the tank 54, and a handle 57 is provided thereon. A coil spring 58 is provided behind the piston 56 in the tank 54 to urge the piston 56 forward. A cartridge (not shown) filled with grease is housed in front of the piston 56 in the tank 54. The cartridge is pressed by the piston 56 which moves forward due to the urging of the coil spring 58, and supplies grease into the front holder 51.

[0059] A pump 60 is provided in the front holder 51. The pump 60 discharges grease supplied from the tank 54 under pressure by the up and down movement of the plunger 50. In addition to the plunger 50, the pump 60 includes an upper cylinder portion 61 and a lower cylinder portion 62. The gap between the upper cylinder portion 61 and the lower cylinder portion 62 communicates with the tank 54. A vertical discharge passage 63 is formed in the lower cylinder portion 62. A check valve 64 is provided at the bottom of the vertical discharge passage 63.

[0060] Next, a lateral discharge passage 66 communicating with the vertical discharge passage 63 is formed facing forward in the lower cylinder portion 62. A front cylinder portion 67 protruding forward is formed on the front surface of the front holder 51. The lateral discharge passage 66 is formed in the center of the front cylinder portion 67, and its front end is opened as a grease discharge port 66A. A hose 68 is connected to the front cylinder portion 67 to guide the grease discharged from the discharge port 66A to a desired location.

[0061] A relief valve 69 is provided on the right side of the front cylindrical portion 67. The relief valve 69 releases the grease to the outside when the pressure of the grease in the lateral discharge passage 66 reaches or exceeds a predetermined pressure. In the grease dispensing device 1 configured as described above, when the tank 54 containing the cartridge is connected to the front holder 51 and the user pulls the trigger 9, the control circuit 80 (see Figure 4) mounted on the control circuit board 18 drives the motor 20 to rotate the rotating shaft 30.

[0062] That is, the control circuit 80 corresponds to an example of a control unit of the present disclosure, and detects the rotation state of the rotor 22 based on a rotation detection signal output from a rotation detection element of the sensor circuit board 28. Then, the control circuit 80 causes a three-phase current to flow in sequence through each coil 24 of the stator 21 according to the detected rotation state of the rotor 22, thereby rotating the rotor 22 (in other words, the rotating shaft 30).

[0063] The rotation of the rotating shaft 30 is reduced in speed by the reduction mechanism 43 and transmitted to the spindle 44, which reduces the speed of rotation of the crank plate 46 together with the spindle 44. This causes the eccentric pin 47 to perform eccentric motion, causing the slider 48 to move up and down, and reciprocating the plunger 50 up and down.

[0064] Then, in the pump 60, the grease that has been forced downward inside the vertical discharge passage 63 of the lower cylinder portion 62 flows into the horizontal discharge passage 66 and is discharged from the discharge port 66A via the hose 68. This discharge operation is repeated as the plunger 50 reciprocates.

[0065] Therefore, when the motor 20 is driven to discharge the grease from the discharge port 66A, the control circuit 80 measures the number of reciprocating movements of the plunger 50 to control the amount of grease discharged. That is, the control circuit 80 can control the actual amount of grease discharged from the discharge port 66A based on the number of reciprocations of the plunger 50 and a reference discharge amount that indicates the amount of grease discharged per one reciprocation of the plunger 50.

[0066] Therefore, in the grease dispensing device 1 of this embodiment, the user sets the number of reciprocating movements of the plunger 50, and the control circuit 80 controls the amount of grease dispensed by reciprocating the plunger 50 the number of reciprocating movements set by the user.

[0067] In order to measure the number of reciprocations of the plunger 50, the crank housing 45 is provided with a reciprocation number detection element 65 (see FIG. 4) that detects the rotation of the crank plate 46 or the position change of the plunger 50 and generates a detection signal for each reciprocation of the plunger 50. This reciprocation number detection element 65 is configured, for example, by a Hall sensor or a proximity switch.

[0068] Then, when the control circuit 80 drives the motor 20 to eject grease from the ejection port 66A, the control circuit 80 stops driving the motor 20 when the measured value of the number of reciprocations of the plunger 50 measured from the detection signal from the reciprocation number detection element 65 reaches a predetermined reciprocation number set value.

[0069] Next, the operation panel 70 is used to set, by external operation, the rotation speed of the motor 20 and the number of reciprocating movements of the plunger 50 when discharging grease from the discharge port 66A, and to display the set values.

[0070] As described above, the operation panel 70 is provided on the front upper surface of the grip portion 5. As shown in Fig. 3, the operation panel 70 is provided with a display circuit 72 including three 7-segment displays 72A, 72B, and 72C, and three button switches 74, 76, and 78.

[0071] The seven-segment displays 72A, 72B, and 72C are arranged side by side in the left-right direction on the front side of the upper surface of the operation panel 70, and are covered with a transparent resin plate from above the operation panel 70. The button switches 74, 76, and 78 are arranged side by side in the left-right direction on the rear side of the seven-segment displays 72A, 72B, and 72C.

[0072] Of the three button switches 74, 76, and 78, the button switch 74 is a switch used to input a command to change the set value to be displayed on the display circuit 72 (hereinafter, referred to as a display changeover switch).

[0073] Moreover, the button switches 76 and 78 are switches (hereinafter referred to as setting switches) used to change the set value displayed on the display circuit 72. That is, the setting switch 76 is a setting switch (+ switch) that increases the set value, and the setting switch 76 is a setting switch (- switch) that decreases the set value. The display changeover switch 74 is also used to confirm the set value changed by operating the setting switches 76, 78.

[0074] Therefore, by operating the display changeover switch 74 of the operation panel 70, the user can cause the display circuit 72 to display the number of reciprocations of the plunger 50 when driving the motor 20 to discharge grease from the discharge port 66A. In addition, the user can change the set value of the number of reciprocations of the plunger 50 by operating the setting switches 76, 78 of the operation panel 70.

[0075] Next, in addition to a control circuit 80 serving as a control unit of the present disclosure, an inverter 82 serving as a drive unit of the present disclosure, a power supply circuit 84, and four pull-up resistors R are mounted on the control circuit board 18. The control circuit board 18 also includes a power supply line connected to the positive electrode side of the battery pack 15 and a ground line connected to the negative electrode side of the battery pack 15.

[0076] The inverter 82 includes high-side switches Q1 to Q3 arranged between the three terminals of the motor 20 and the power line of the control circuit board 18, and low-side switches Q4 to Q6 arranged between the three terminals of the motor 20 and the ground line of the control circuit board 18.

[0077] The inverter 82 causes three-phase current to flow through each coil of the stator 21 of the motor 20 by turning on and off each switch Q1 to Q6 in response to a drive control signal from the control circuit 80, thereby driving the motor 20. The high-side switches Q1 to Q3 and the low-side switches Q4 to Q6 are in the form of semiconductor switches such as FETs or bipolar transistors.

[0078] The power supply circuit 84 is provided between the power supply line and the ground line of the control circuit board 18, and generates a DC constant voltage (hereinafter referred to as the power supply voltage) Vc for supplying power to the control circuit 80. The power supply voltage Vc generated by the power supply circuit 84 is supplied to the display circuit 72 of the operation panel 70, the sensor circuit board 28, and the reciprocation number detection element 65, in addition to the control circuit 80.

[0079] The display circuit 72 of the operation panel 70 receives a display control signal output from the control circuit 80 and displays information on three 7-segment displays 72A, 72B, and 72C. The sensor circuit board 28 also includes, as rotation detection elements, three Hall elements 28A, 28B, and 28C arranged around the rotor 22 of the motor 20, as shown in Fig. 5. The three Hall elements 28A to 28C output rotation signals that correspond to the respective phases of the motor 20 and whose increase / decrease direction is reversed every time the rotor 22 rotates through 180 electrical degrees.

[0080] The sensor circuit board 28 or the control circuit 80 is provided with a waveform shaping circuit (not shown) that shapes the waveforms of the rotation signals from the three Hall elements 28A to 28C to generate rotation detection signals that indicate the rotation position of the rotor 22 at intervals of 60 electrical degrees. The control circuit 80 detects the rotation position of the motor 20 and calculates the rotation speed of the motor 20 based on the rotation detection signals from this waveform shaping circuit.

[0081] Next, the four pull-up resistors R apply a power supply voltage Vc to one end of the trigger switch 8, the display changeover switch 74, and the setting switches 76 and 78, and input the on / off state of each of the switches 8, 74 to 78 to the control circuit 80.

[0082] That is, the other end of each of the switches 8, 74 to 78 is connected to the ground line of the control circuit board. Therefore, when the switches 8, 74 to 78 are in the off state, the connection point between each of the switches 8, 74 to 78 and the pull-up resistor R is at the high level, which is the same potential as the power supply voltage Vc. On the other hand, when the switches 8, 74 to 78 are in the on state, the connection point between each of the switches 8, 74 to 78 and the pull-up resistor R is at the low level, which is the same potential as the ground line.

[0083] For this reason, the connection points between each of the switches 8, 74 to 78 and the pull-up resistor R are connected to the control circuit 80, and the control circuit 80 can detect the on / off state of each of the switches 8, 74 to 78 based on the potential at the connection points.

[0084] Next, the control circuit 80 includes a known microcomputer having, for example, a CPU 80A and a semiconductor memory 80B such as a ROM, a RAM, or a flash memory. The control circuit 80 realizes various functions by the CPU 80A executing a program stored in a non-transient real-world recording medium. In this example, the semiconductor memory 80B corresponds to the non-transient real-world recording medium storing the program. The number of microcomputers constituting the control circuit 80 may be one or more.

[0085] 5 are realized by the CPU 80A executing a program in the control circuit 80. That is, the functions include those of a switch detection unit 91, a reciprocation count setting unit 92, a display control unit 93, a reciprocation count calculation unit 94, a reciprocation count difference calculation unit 95, a motor drive control unit 96, and an operation control unit 97.

[0086] It should be noted that these functions of the control circuit 80 are not limited to software, and some or all of the functions may be realized using hardware that combines logic circuits, analog circuits, and the like.

[0087] Here, the switch detection unit 91 has a function of detecting the on / off state of the above four switches 8, 74 to 78. The reciprocation number setting unit 92 has a function of setting the number of reciprocations of the plunger 50 when discharging grease in accordance with inputs from the display changeover switch 74 and the setting switches 76 and 78. The display control unit 93 has a function of causing the display circuit 72 to display the number of reciprocations of the plunger 50 set by the reciprocation number setting unit 92.

[0088] On the other hand, the reciprocation number calculation unit 94 is a function that measures the number of reciprocations of the plunger 50 by counting the detection signal input from the reciprocation number detection element 65. Also, the reciprocation number difference calculation unit 95 is a function that calculates the difference between the reciprocation number setting value set by the reciprocation number setting unit 92 and the reciprocation number measurement value measured by the reciprocation number calculation unit 94, that is, the remaining number of reciprocations that the plunger 50 should reciprocate when discharging grease.

[0089] Next, the motor drive control section 96 has a function of generating a drive control signal indicating the on / off timing of each of the switches Q1 to Q6 in the inverter 82 according to the rotational position of the motor 20 in accordance with a command from the operation control section 97, and outputting the signal to the inverter 82. When a drive control signal is output from the control circuit 80 by this function, each of the switches Q1 to Q6 in the inverter 82 is turned on / off, causing a current to flow through each phase of the motor 20, and causing the motor 20 to rotate.

[0090] Furthermore, the operation control unit 97 has a function of outputting a drive command to the motor drive control unit 96 when the switch detection unit 91 detects that the trigger switch 8 is in the on state, and outputting a stop command to the motor drive control unit 96 when the trigger switch 8 switches to the off state. Therefore, when a drive command is output to the motor drive control unit 96 by this function, the motor 20 rotates, the plunger 50 reciprocates at a speed corresponding to the rotation speed, and the grease is discharged from the discharge port 66A.

[0091] Furthermore, the drive command output from the operation control unit 97 to the motor drive control unit 96 includes a target rotation speed at which the motor 20 is driven. The motor drive control unit 96 then calculates the rotation speed of the motor 20 based on the rotation detection signal from the sensor circuit board 28, and drives the motor 20 so that the rotation speed of the motor 20 becomes the target rotation speed.

[0092] Incidentally, in the grease discharging device 1, the discharging speed of the grease from the discharge port 66A changes depending on the rotation speed of the motor 20. For this reason, as shown in Fig. 6A, if the target rotation speed of the motor 20 is set to a low speed, the time required to discharge a certain amount of grease, defined by the number of reciprocating movements of the plunger 50, from the discharge port 66A becomes longer, and the grease cannot be efficiently discharged.

[0093] On the other hand, in order to perform the grease discharge operation efficiently, the operation time can be shortened by setting the target rotation speed of the motor 20 to a high speed as shown in Fig. 6B. However, in this case, the plunger 50 reciprocates at high speed due to the rotation of the motor 20, so that a certain amount of grease is discharged from the discharge port 66A, and even if the drive of the motor 20 is stopped and the brake is applied, the motor 20 cannot be stopped quickly.

[0094] Therefore, the time from when the drive of the motor 20 is stopped until the plunger 50 actually stops and the grease stops being discharged becomes longer, and during that time, excess grease is discharged, making it impossible to control the amount of grease discharged to the desired amount.

[0095] 7, when the trigger switch 8 is turned on and the motor 20 starts to drive, the target rotation speed is set to high to discharge the grease at a high speed. Then, when the difference in the number of reciprocations calculated by the reciprocation number difference calculation unit 95, that is, the remaining number of reciprocations to be made by the plunger 50, falls to a predetermined threshold value (time t1), the target rotation speed is switched to low.

[0096] As a result, when the measured number of reciprocations of the plunger 50 reaches the set number of reciprocations (time t2) and the drive of the motor 20 is stopped, the motor 20 and the plunger 50 stop shortly thereafter (time t3), thereby preventing excess grease from being discharged.

[0097] Next, the control process executed by the control circuit 80 to control the amount of grease discharged will be described with reference to the flowcharts shown in Figures 8 and 9. Note that this flowchart represents a program executed by the CPU 80A to realize each of the above-mentioned functions. Also, since this control process is a process in which the motor 20 is rotated by operating the trigger switch 8 to discharge grease, the display circuit 72 is assumed to display the set value of the number of reciprocations of the plunger 50, which indicates the amount of grease discharged.

[0098] As shown in FIG. 8, when the above control process is started, first, in S110, the process is executed as a reciprocation count difference calculation unit 95, which calculates the difference between the reciprocation count set value and the reciprocation count measured value of the plunger 50 (reciprocation count set value-reciprocation count measured value).

[0099] Next, in S120, it is determined whether or not the trigger switch 8 is on. If the trigger switch 8 is on, the process proceeds to S200, and if the trigger switch 8 is not on, the process proceeds to S130.

[0100] In S130, since the trigger switch 8 is in the OFF state, the driving of the motor 20 is stopped, and the process proceeds to S140. Note that in S130, in order to quickly stop the rotation of the motor 20, not only is the power supply to the motor 20 stopped, but a braking force is generated on the motor 20 by a so-called short-circuit brake.

[0101] In S140, it is determined whether the difference in the number of reciprocations of the plunger 50 calculated in S110 is "0", that is, whether the measured value of the number of reciprocations has reached the set value of the number of reciprocations. If the difference in the number of reciprocations is "0", the process proceeds to S150, where the measured value of the number of reciprocations is reset, and then the process proceeds to S160. If the difference in the number of reciprocations is not "0", the process proceeds directly to S160.

[0102] In S160, it is determined whether or not the setting switches 76, 78 have been operated. If the setting switches 76, 78 have been operated, the measured reciprocation count value is reset in S170, and the reciprocation count set value is changed in response to the operation of the setting switches 76, 78 in the following S180, and then the process proceeds to S190. If the setting switches 76, 78 have not been operated, the process proceeds directly to S190. In S190, the reciprocation count set value changed in S180 is displayed on the display circuit 72, and the process proceeds to S110.

[0103] Next, in S200, similar to S140, it is determined whether the difference in the number of reciprocations of the plunger 50 calculated in S110 is "0". If it is determined in S200 that the difference in the number of reciprocations is "0" and the measured number of reciprocations has reached the set number of reciprocations, the process proceeds to S210, where the driving of the motor 20 is stopped, and the process proceeds to S190. Note that in S210, similar to S130 described above, a braking force is generated in the motor 20 to quickly stop the rotation of the motor 20.

[0104] On the other hand, if it is determined in S200 that the reciprocation number difference is not "0", it is necessary to discharge grease from the discharge port 66A, so the process proceeds to S300, and motor drive control is performed in the procedure shown in Fig. 9. Then, when the motor drive control in S300 ends, the process proceeds to S190.

[0105] 9, the motor drive control is started in S310 by determining whether the reciprocation number difference calculated in S110 is less than a preset threshold value. If it is determined in S310 that the reciprocation number difference is less than the threshold value, the process proceeds to S320, where the motor 20 is driven so that the rotation speed of the motor 20 becomes a first speed.

[0106] Furthermore, if it is determined in S310 that the reciprocation number difference is not less than the threshold (that is, is equal to or greater than the threshold), the process proceeds to S330, where the motor 20 is driven so that the rotation speed of the motor 20 becomes a second speed that is higher than the first speed.

[0107] The first speed and the second speed are target rotational speeds when driving the motor 20. Since the second speed is higher than the first speed, as shown in FIG. 7, after the motor 20 starts to drive, the motor 20 is driven at high speed at the second speed until time t1 at which the difference in the number of reciprocating motions becomes equal to or greater than a threshold value.

[0108] Then, when the reciprocation number difference decreases to the threshold value while the motor 20 is being driven at high speed, the target rotation speed of the motor 20 is switched to the first speed, and the motor 20 is driven at the first speed.

[0109] When the motor 20 is driven to the first speed or the second speed in S320 or S330, the process proceeds to S400, in which the number of reciprocations of the plunger 50 is measured and the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0110] Therefore, as shown in FIG. 7, when the low-speed drive of motor 20 starts at time t1 and the difference in the number of reciprocating motions becomes "0" at time t2, the drive of motor 20 is stopped and the rotation of motor 20 is stopped due to the braking force generated in motor 20 by the short-circuit brake.

[0111] When the drive of motor 20 is stopped in this manner, the rotation speed of motor 20 is reduced to the second speed, so the time until motor 20 actually stops after the drive of motor 20 is stopped is shorter than the stop time shown in Figure 6B.

[0112] Therefore, according to the grease dispensing device 1 of this embodiment, by rotating the motor 20 at high speed immediately after starting the grease dispensing operation, it is possible to suppress the operation time from being lengthened and to suppress the amount of grease dispensed after the driving of the motor 20 is stopped. Therefore, it is possible to perform the grease dispensing operation efficiently and more appropriately.

[0113] Here, in the present embodiment, in the motor drive control of S300, the rotation speed of the motor 20 is switched between two speeds, a high speed second speed and a low speed first speed, depending on the difference in the number of reciprocating movements.

[0114] However, in the motor drive control of S300, the rotation speed of the motor 20 may be switched between three or more stages in accordance with the difference in the number of reciprocations to decelerate the motor 20 in stages. Also, the rotation speed of the motor 20 may be continuously decelerated as the difference in the number of reciprocations decreases.

[0115] Therefore, the motor drive control performed when controlling the rotation speed of the motor 20 in this manner will be described as first to third modified examples of the first embodiment. 2-1-1. First modified example As shown in FIG. 10, in the motor drive control of the first modified example, in S312, it is determined whether the difference in the number of reciprocating movements is less than a preset first threshold value, and if it is less than the first threshold value, in S320, the motor 20 is driven so that the rotation speed becomes the first speed.

[0116] Furthermore, if it is determined in S312 that the round trip number difference is not less than the first threshold (that is, is equal to or greater than the first threshold), the process proceeds to S314, where it is determined whether the round trip number difference is less than a second threshold that is greater than the first threshold.

[0117] Then, when it is determined in S314 that the reciprocation number difference is less than the second threshold value, the process proceeds to S330, where the motor 20 is driven so that the rotation speed becomes a second speed that is higher than the first speed.

[0118] Furthermore, if it is determined in S314 that the reciprocation number difference is not less than the second threshold (i.e., is equal to or greater than the second threshold), the process proceeds to S340, where the motor 20 is driven so that the rotation speed becomes a third speed that is higher than the second speed.

[0119] Then, when the motor 20 is driven to the first to third speeds in S320 to S340, the process proceeds to S400, where the number of reciprocations of the plunger 50 is measured and the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0120] In this way, according to the motor drive control of the first modified example, after the motor 20 starts to be driven, the rotational speed of the motor 20 is switched in sequence from the third speed to the second speed to the first speed, and so on, depending on the difference in the number of reciprocating movements of the plunger 50.

[0121] Therefore, in this first modified example, the rotational speed of motor 20 can be gradually reduced until the driving of motor 20 is stopped, and the time until motor 20 actually stops after the driving of motor 20 is stopped can be more reliably shortened.

[0122] In the motor drive control shown in FIG. 10, the target rotation speed of the motor 20 is switched between three stages, but as illustrated in FIG. 11, the target rotation speed of the motor 20 may be switched between four or more stages.

[0123] That is, Fig. 11 shows the change in the rotation speed of the motor 20 and the number of reciprocations of the plunger 50 when the target rotation speed of the motor 20 is switched between six levels. In this case, the motor drive control shown in Fig. 10 can be implemented in the same manner as above by performing the process of determining the difference in the number of reciprocations and the threshold value in S312 and S314 in five levels.

[0124] By increasing the number of switching stages of the target rotation speed of the motor 20 in this manner, it is possible to ensure a high-speed operation section before the motor 20 is stopped, even when the amount of grease discharged is small and the set value for the number of reciprocating movements of the plunger 50 is small.

[0125] 2-1-2. Second modified example 12, in the motor drive control of the second modified example, first, in S350, the drive speed (i.e., the target rotation speed) of the motor 20 is calculated based on the difference in the number of reciprocations of the plunger 50. Specifically, the target rotation speed of the motor 20 is calculated using the following equation (1) in which the difference in the number of reciprocations, a preset coefficient, and a preset minimum speed are used as parameters.

[0126] Target rotation speed = number of reciprocations difference x coefficient + minimum speed ... (1) Next, in S360, the motor 20 is driven at the drive speed calculated in S350. Then, in S400, the number of reciprocations of the plunger 50 is measured, the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0127] In this way, in the second modified example, the drive speed of the motor 20 is set based on the difference in the number of reciprocations of the plunger 50, so that immediately after the drive of the motor 20 starts, the drive speed of the motor 20 is set to the maximum speed corresponding to the set value of the number of reciprocations of the plunger 50. Then, after the drive of the motor 20 starts, as the measured value of the number of reciprocations increases and the difference in the number of reciprocations decreases, the drive speed of the motor 20 decreases.

[0128] Therefore, the driving speed of the motor 20 is continuously reduced according to the difference in the number of reciprocating motions after the motor 20 starts to drive, and the rotational speed of the motor 20 when the driving of the motor 20 is stopped can be sufficiently reduced from the rotational speed immediately after the motor 20 starts to drive.

[0129] Therefore, in this second modified example as well, it is possible to reduce the amount of grease dispensed after the motor 20 is stopped from driving while preventing the grease dispensing operation time by the grease dispensing device 1 from becoming too long, making it possible to carry out the grease dispensing operation efficiently and properly.

[0130] 2-1-3.Third modified example 13, in the motor drive control of the third modified example, first, in S310, it is determined whether or not the difference in the number of reciprocations of the plunger 50 is less than a preset threshold value. Then, if it is determined in S310 that the difference in the number of reciprocations is not less than the threshold value (i.e., is equal to or greater than the threshold value), the process proceeds to S370, where the motor 20 is driven at a preset maximum speed, and then the process proceeds to S400.

[0131] On the other hand, if it is determined in S310 that the difference in the number of reciprocations is less than the threshold value, the process proceeds to S380, where the driving speed of the motor 20 (i.e., the target rotational speed) is calculated based on the difference in the number of reciprocations of the plunger 50 using the above-mentioned equation (1), and the process proceeds to S390.

[0132] In S390, the motor 20 is driven at the drive speed calculated in S380, and the process proceeds to S400. Then, in S400, as in the above embodiment and each of the above modifications, the number of reciprocations of the plunger 50 is measured, the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0133] 14, in the third modified example, the motor 20 is driven at a preset maximum speed from when the motor 20 starts to be driven until time t1 when the difference in the number of reciprocations of the plunger 50 becomes less than the threshold value. After time t1, the target rotation speed of the motor 20 is set according to the difference in the number of reciprocations, so that the rotation speed of the motor 20 decreases as the difference in the number of reciprocations becomes smaller.

[0134] Therefore, in the third modified example as well, the rotation speed of the motor 20 when the drive of the motor 20 is stopped can be sufficiently reduced from the maximum speed immediately after the drive of the motor 20 is started, and the same effect as the second modified example can be obtained. Moreover, in the third modified example, the motor 20 is driven at the maximum speed after the drive of the motor 20 is started until the reciprocation number difference reaches the threshold value, so that the grease dispensing operation time can be shortened compared to the second modified example.

[0135] 2-1-4.Fourth modified example Next, in the control process shown in FIG. 8, even if the trigger switch 8 is turned off and the driving of the motor 20 is stopped after the driving of the motor 20 is started, the reciprocation count measurement value is not reset until it is determined in S140 that the reciprocation count difference is "0".

[0136] This is because the measured value of the number of reciprocations is held until the difference in the number of reciprocations becomes "0" by driving the motor 20, so that the grease dispensing operation can be continued the next time the trigger switch 8 is turned on.

[0137] In contrast, in the fourth modified example, the control process is carried out in the procedure shown in FIG. 15. When it is determined in S120 that the trigger switch 8 is in the off state, the reciprocation count measurement value is reset in S150 without determining whether the reciprocation count difference is “0” in S140.

[0138] Therefore, in the fourth modified example, when the trigger switch 8 is once switched to the OFF state and then switched to the ON state again, the grease dispensing operation can be performed from the beginning.

[0139] In the control process of the fourth modified example shown in FIG. 15, when the trigger switch 8 is switched to the OFF state, the reciprocation count measurement value is reset, and therefore the process of S170 shown in FIG. 8 is not performed.

[0140] Furthermore, when the trigger switch 8 is in the OFF state, the determination of the difference in the number of reciprocating movements in S140 is not performed. Therefore, the calculation process of the difference in the number of reciprocating movements in S110 is performed in S220 when it is determined in S120 that the trigger switch 8 is in the ON state.

[0141] Then, when the difference in the number of reciprocations is calculated in S220, the process proceeds to S230, in which it is determined whether the difference in the number of reciprocations of the plunger 50 calculated in S220 is "0" or not. If the difference in the number of reciprocations is "0", the process proceeds to S240, in which the drive of the motor 20 is stopped.

[0142] Furthermore, if it is determined in S230 that the reciprocation number difference is not "0", the process proceeds to S300, where the motor drive control described above is performed. After the process of S240 or S300 is executed, the process proceeds to S190. The motor drive control of S300 may be performed according to the procedure shown in FIG. 9, or may be performed according to the same procedures as those of the first to third modified examples.

[0143] 2-2. Second embodiment Next, a second embodiment of the present disclosure will be described. The grease dispensing device 1 of this embodiment is configured almost the same as that of the first embodiment, and differs from the first embodiment in that, as shown in FIG. 16, a reciprocation count detection element 65 is not provided, and part of the functional configuration and control processing of the control circuit 80 differs from that of the first embodiment.

[0144] Therefore, in this embodiment, the points different from the first embodiment will be described, and a description of the points that are the same as in the first embodiment will be omitted. 16, in this embodiment, there is no reciprocation number detection element 65, and it is not possible to measure the number of reciprocations of the plunger 50 using a detection signal from the reciprocation number detection element 65. For this reason, the control circuit 80 is provided with the functions of a rotation number calculation unit 98 and a rotation number difference calculation unit 99 of the motor 20, instead of the functions of the reciprocation number calculation unit 94 and the reciprocation number difference calculation unit 95 of the plunger 50.

[0145] Here, the rotation count calculation unit 98 has a function of measuring the number of rotations of the motor 20, which corresponds to the number of reciprocating movements of the plunger 50, by counting the number of rotations of the motor 20 after the start of driving based on the rotation detection signal from the sensor circuit board 28.

[0146] In addition, the rotation count difference calculation unit 99 has a function of converting the set value of the number of reciprocating movements of the plunger 50 into a target value of the number of rotations of the motor 20 based on the reduction ratio (hereinafter referred to as the gear ratio) of the reduction mechanism 43, and calculating the difference between the target value of the number of rotations and the value measured by the rotation count calculation unit 98.

[0147] Then, when the difference in the number of rotations calculated by the rotation number difference calculation unit 99 falls to a predetermined threshold value after starting high-speed driving of the motor 20, the operation control unit 97 switches the rotation speed of the motor 20 to low. Also, when the measured value of the number of rotations of the motor 20 reaches the target number of rotations value, the operation control unit 97 stops driving the motor 20. Therefore, in this embodiment as well, when the driving of the motor 20 is stopped, the motor 20 and the plunger 50 come to a stop in a short time, and the same effect as in the first embodiment can be obtained.

[0148] Next, the control process of this embodiment that is executed to control the amount of grease discharged in this manner will be described with reference to the flowcharts shown in FIGS. 17, in the control process of this embodiment, first, in S500, a target value of the number of revolutions of the motor 20 is calculated based on a set value of the number of reciprocations of the plunger 50 and a gear ratio of the speed reduction mechanism 43. Then, in the following S510, a process is executed as a rotation number difference calculation unit 99 that calculates the difference between the target value of the number of revolutions of the motor 20 and the measured value (target value of the number of revolutions-measured value of the number of revolutions).

[0149] Next, in S520, similarly to S120 described above, it is determined whether or not the trigger switch 8 is on. If the trigger switch 8 is on, the process proceeds to S600, and if the trigger switch 8 is not on, the process proceeds to S530.

[0150] In S530, since the trigger switch 8 is in the OFF state, the driving of the motor 20 is stopped as in S130 described above, and the process proceeds to S540. In S540, it is determined whether the rotation number difference of the plunger 50 calculated in S510 is "0". If the rotation number difference is "0", the process proceeds to S550, where the rotation number measurement value is reset, and then the process proceeds to S560. If the rotation number difference is not "0", the process proceeds directly to S560.

[0151] In S560, it is determined whether or not the setting switches 76, 78 have been operated. If the setting switches 76, 78 have been operated, the rotation count measurement value is reset in S570, and then in S580, the reciprocation count setting value is changed in response to the operation of the setting switches 76, 78, and the process proceeds to S590. If the setting switches 76, 78 have not been operated, the process proceeds directly to S590. In S590, the reciprocation count setting value changed in S580 is displayed on the display circuit 72, as in S190 described above, and the process proceeds to S500.

[0152] Next, in S600, it is determined whether the rotation count difference of the motor 20 calculated in S510 is 0. If it is determined in S600 that the rotation count difference is 0 and the rotation count measurement value has reached the rotation count target value, the process proceeds to S610, where the driving of the motor 20 is stopped as in S210 described above, and the process proceeds to S590.

[0153] On the other hand, if it is determined in S600 that the rotation number difference is not "0", it is necessary to discharge grease from the discharge port 66A, so the process proceeds to S700, and motor drive control is performed in the procedure shown in Fig. 18. Then, when the motor drive control in S700 ends, the process proceeds to S590.

[0154] 18, the motor drive control is started by determining in S710 whether the rotation number difference calculated in S510 is less than a preset threshold value. If it is determined in S710 that the rotation number difference is less than the threshold value, the process proceeds to S720, where the motor 20 is driven so that the rotation speed of the motor 20 becomes a first speed.

[0155] Furthermore, if it is determined in S710 that the rotation count difference is not less than the threshold (that is, is equal to or greater than the threshold), the process proceeds to S730, where the motor 20 is driven so that the rotation speed of the motor 20 becomes a second speed that is greater than the first speed.

[0156] As a result, after the motor 20 starts to drive, the motor 20 is driven at high speed at the second speed while the rotation count difference is equal to or greater than the threshold value, and when the rotation count difference decreases to the threshold value, the target rotation speed is switched to the first speed, and the motor 20 is driven at low speed at the first speed.

[0157] Then, when the motor 20 is driven to the first speed or the second speed in S720 or S730, the process proceeds to S800, where the number of rotations of the motor 20 is measured, the measured value of the number of rotations is updated, and the motor drive control ends.

[0158] Therefore, in this embodiment, the rotation speed of the motor 20 is switched from high to low by the time the rotation count difference of the motor 20 becomes "0" and the driving of the motor 20 is stopped.

[0159] Therefore, in this embodiment as well, the time until the rotation of the motor 20 stops after the driving of the motor 20 is stopped can be made shorter than the stop time shown in FIG. 6B, and the same effect as in the first embodiment can be obtained.

[0160] Here, the motor drive control process shown in Fig. 18 can be modified in the same manner as the first to third modified examples of the first embodiment. Moreover, the control process shown in Fig. 17 can also be modified in the same manner as the fourth modified example of the first embodiment.

[0161] Next, first to fourth modified examples of this embodiment will be described in correspondence with the first to fourth modified examples of the first embodiment. 2-2-1. First modified example As shown in FIG. 19, in the motor drive control of the first modified example, in S712, it is determined whether the rotation count difference is less than a preset first threshold value, and if it is less than the first threshold value, in S720, the motor 20 is driven so that the rotation speed becomes the first speed.

[0162] Furthermore, if it is determined in S712 that the rotation count difference is not less than the first threshold (i.e., is equal to or greater than the first threshold), the process proceeds to S714, in which it is determined whether the rotation count difference is less than a second threshold that is greater than the first threshold.

[0163] Then, when it is determined in S714 that the rotation number difference is less than the second threshold value, the process proceeds to S730, where the motor 20 is driven so that the rotation speed becomes a second speed that is higher than the first speed.

[0164] Furthermore, if it is determined in S714 that the rotation count difference is not less than the second threshold (i.e., is equal to or greater than the second threshold), the process proceeds to S740, where the motor 20 is driven so that the rotation speed becomes a third speed that is even higher than the second speed.

[0165] Then, when the motor 20 is driven to the first to third speeds in S720 to S740, the process proceeds to S800, where the number of reciprocations of the motor 20 is measured and the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0166] In this way, according to the motor drive control of the first modified example, after the drive of the motor 20 starts, the rotation speed of the motor 20 is switched in sequence from the third speed to the second speed to the first speed, and so on, depending on the difference in the number of rotations of the motor 20.

[0167] Therefore, in this first modified example, the rotational speed of motor 20 can be gradually reduced until the driving of motor 20 is stopped, and the time until motor 20 actually stops after the driving of motor 20 is stopped can be more reliably shortened.

[0168] In the motor drive control shown in FIG. 19, the target rotation speed of the motor 20 is switched between three stages. However, similar to the first modified example of the first embodiment, the target rotation speed of the motor 20 may be switched between multiple stages, such as four or more stages.

[0169] 2-2-2. Second modified example 20, in the motor drive control of the second modified example, first, in S750, the drive speed (i.e., the target rotation speed) of the motor 20 is calculated based on the rotation number difference of the motor 20. Specifically, the target rotation speed of the motor 20 is calculated using the following equation (2) in which the rotation number difference, a preset coefficient, and a preset minimum speed are used as parameters.

[0170] Target rotation speed = rotation speed difference x coefficient + minimum speed ... (2) Next, in S760, the motor 20 is driven at the drive speed calculated in S750. Then, in S800, the number of rotations of the motor 20 is measured, the measured value of the number of rotations is updated, and the motor drive control is terminated.

[0171] In this way, in the second modified example, the drive speed of the motor 20 is set based on the rotation count difference of the motor 20, so that immediately after the drive of the motor 20 starts, the drive speed of the motor 20 is set to the maximum speed corresponding to the rotation count target value of the motor 20. Then, after the drive of the motor 20 starts, as the rotation count measurement value increases and the rotation count difference becomes smaller, the drive speed of the motor 20 decreases.

[0172] Therefore, the drive speed of the motor 20 is continuously reduced according to the difference in the number of rotations after the drive of the motor 20 starts, and the rotation speed of the motor 20 when the drive of the motor 20 is stopped can be sufficiently reduced from the rotation speed immediately after the drive of the motor 20 starts. Therefore, in this second modified example, the same effect as the second modified example of the first embodiment can be obtained.

[0173] 2-2-3.Third modified example 21, in the motor drive control of the third modified example, first, in S710, it is determined whether or not the rotation count difference of the motor 20 is less than a preset threshold value. Then, if it is determined in S710 that the rotation count difference is not less than the threshold value (i.e., is equal to or greater than the threshold value), the process proceeds to S770, where the motor 20 is driven at a preset maximum speed, and then the process proceeds to S800.

[0174] On the other hand, if it is determined in S710 that the rotation count difference is less than the threshold value, the process proceeds to S780, where the drive speed of motor 20 (i.e., the target rotation speed) is calculated based on the rotation count difference of motor 20 using the above-mentioned equation (2), and the process proceeds to S790.

[0175] In S790, the motor 20 is driven at the drive speed calculated in S780, and the process proceeds to S800. In S800, the number of reciprocations of the motor 20 is measured, the measured value of the number of reciprocations is updated, and the motor drive control ends.

[0176] In this manner, in the third modified example, the motor 20 is driven at a preset maximum speed from when the motor 20 starts to be driven until time t1 at which the rotation count difference of the motor 20 falls below the threshold value. Then, after time t1, the target rotation speed of the motor 20 is set according to the rotation count difference, so that the rotation speed of the motor 20 decreases as the rotation count difference becomes smaller.

[0177] Therefore, in the third modified example as well, the rotation speed of the motor 20 when the drive of the motor 20 is stopped can be sufficiently reduced from the maximum speed immediately after the drive of the motor 20 is started, and the same effect as the second modified example can be obtained. Moreover, in the third modified example, the motor 20 is driven at the maximum speed after the drive of the motor 20 is started until the rotation number difference reaches the threshold value, so that the grease dispensing operation time can be shortened compared to the second modified example.

[0178] 2-2-4.Fourth modified example In the fourth modification, the control circuit 80 performs a control process shown in FIG. 22 instead of the control process shown in FIG.

[0179] That is, in this fourth modified example, when the control process is started, first, in S520, it is determined whether or not the trigger switch 8 is in the OFF state. Then, if it is determined in S520 that the trigger switch 8 is in the OFF state, the driving of the motor 20 is stopped in S530, and thereafter, the rotation count measurement value is reset in S550 without performing the determination process in S540.

[0180] Therefore, in this fourth modified example, similar to the fourth modified example of the first embodiment, when the trigger switch 8 is once switched to the off state and then the trigger switch 8 is next switched to the on state, the grease dispensing operation can be performed from the beginning.

[0181] The control process of this fourth modified example is almost the same as the control process shown in FIG. 17, but when the trigger switch 8 is switched to the off state, the reciprocation count measurement value is reset, so the process of S570 shown in FIG. 17 is not performed.

[0182] In addition, when the trigger switch 8 is in the OFF state, the determination of the difference in the number of reciprocating movements in S540 is not performed. Therefore, the calculation processes of S500 and S510 shown in FIG. 17 are executed in S620 and S630 when it is determined in S520 that the trigger switch 8 is in the ON state.

[0183] Then, when the rotation count difference of the motor 20 is calculated in S630, the process proceeds to S640, where it is determined whether the rotation count difference of the motor 20 is "0" or not. If the rotation count difference is "0", the process proceeds to S650, where the drive of the motor 20 is stopped.

[0184] If it is determined in S640 that the rotation number difference is not 0, the process proceeds to S700, where the motor drive control described above is performed. After the process of S650 or S700 is executed, the process proceeds to S590.

[0185] In addition, in the control processing of the fourth modified example, the motor drive control of S700 may be performed according to the procedure shown in Figure 18, or may be performed according to the same procedures as those of the first to third modified examples described in Figures 19 to 21.

[0186] 2-3. Other embodiments Although the embodiments for carrying out the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be carried out in various modified forms.

[0187] For example, in the above embodiment, the control circuit 80 is described as setting a target rotational speed of the motor 20, and reducing the target rotational speed in accordance with the difference between the set value and the measured value of the number of reciprocations of the plunger 50, or the difference between the set value and the measured value of the number of rotations of the motor 20.

[0188] However, since the rotation speed of motor 20 varies depending on the drive duty of inverter 82, which is set to control the current supplied to motor 20, the drive duty of inverter 82 may be set instead of the target rotation speed. As in the above embodiment, the same effect as in the above embodiment can be obtained even if the drive duty is reduced from an initial value corresponding to the target rotation speed in accordance with the difference in the number of reciprocations or the difference in the number of rotations.

[0189] In addition, multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0190] In addition, the present disclosure can be realized in various forms, such as a grease dispensing device, a system that includes a grease dispensing device as a component, a program for causing a computer to function as a grease dispensing device, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a method for detecting the amount of grease dispensed. [Explanation of symbols]

[0191] 1... grease discharge device, 20... motor, 50... plunger, 60... pump, 80... control circuit, 82... inverter.

Claims

1. A motor; a pump including a plunger that is reciprocated by rotation of the motor, the pump being configured to discharge the grease supplied from the tank through a discharge port by the reciprocating movement of the plunger; A drive unit configured to drive the motor to reciprocate the plunger; a control unit configured to, when receiving a command to dispense the grease from an outside source, drive the motor at a predetermined rotation speed via the drive unit to reciprocate the plunger, measure the number of reciprocations of the plunger, and stop driving the motor when the measured value of the number of reciprocations reaches a preset value; Equipped with The control unit is configured to drive the motor at the predetermined rotational speed, and then reduce the rotational speed of the motor depending on the difference between the measured value of the number of reciprocations and the set value.

2. The grease dispensing device according to claim 1, The control unit is configured to continuously or stepwise reduce the rotational speed of the motor from the specified rotational speed so that the rotational speed of the motor decreases as the difference between the measured value of the number of reciprocations and the set value decreases.

3. The grease dispensing device according to claim 1, The control unit is configured to measure the number of rotations of the motor as a parameter representing the number of reciprocating movements of the plunger, drive the motor at the predetermined rotational speed, and then reduce the rotational speed of the motor depending on the difference between the measured value of the number of rotations and a rotational speed set value corresponding to the set value, and stop driving the motor when the measured value of the number of rotations reaches the rotational speed set value.

4. The grease dispensing device according to claim 3, The control unit is configured to continuously or stepwise reduce the rotational speed of the motor from the predetermined rotational speed so that the rotational speed of the motor decreases as the difference between the measured value of the rotational speed and the set value of the rotational speed becomes smaller.

5. The grease discharge device according to any one of claims 1 to 4, an operation unit configured to input the grease discharge command by an external operation, The control unit is configured to stop driving the motor and clear the measurement value when the input of the discharge command from the operation unit is stopped while the motor is being driven.

6. The grease discharge device according to any one of claims 1 to 4, an operation unit configured to input the grease discharge command by an external operation, the control unit is configured to stop driving the motor and hold the measurement value when the input of the discharge command from the operation unit is stopped while driving the motor, and to resume driving the motor and measuring the measurement value based on the measurement value when the input of the discharge command from the operation unit is resumed.

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