Electric oil injector

Abstract

We provide an electric lubricator that offers superior convenience. [Solution] One aspect of the present disclosure provides an electric lubricator comprising a motor, a drive circuit, a pump, a drive switch, a selection switch, and a control circuit. The selection switch is manually operated by the user to select a first mode or a second mode. The first mode and the second mode are operating modes of the electric lubricator, where the first mode associates the amount of operation of the drive switch with the rotational speed in a first relationship, and the second mode associates the amount of operation of the drive switch with the rotational speed in a second relationship different from the first relationship. The control circuit controls the motor via the drive circuit based on the actual amount of operation of the manually operated drive switch and the first mode or second mode selected via the selection switch.

Description

Technical Field

[0001] This disclosure relates to an electric grease injector.

Background Art

[0002] The grease discharge device described in Patent Document 1 includes a trigger, a pump for discharging grease, a motor for operating the pump, an inverter for driving the motor, and a control circuit. The control circuit controls the inverter to rotate the motor at a rotational speed corresponding to the amount of pull of the trigger. Thereby, the pump operates at a speed corresponding to the rotational speed of the motor to discharge grease.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The user cannot adjust the operation of the grease discharge device other than by adjusting the rotational speed of the motor by the amount of pull of the trigger. Therefore, there is room for improvement in the convenience of the grease discharge device.

[0005] One aspect of this disclosure provides an electric grease injector with excellent convenience.

Means for Solving the Problems

[0006] An electric lubricator in one aspect of the present disclosure comprises a motor, a drive circuit, a pump, a drive switch, a selection switch, and a control circuit. The motor is configured to generate a driving force. The drive circuit is configured to drive the motor. The pump has a discharge port configured to discharge lubricant and is configured to discharge lubricant from the discharge port at a speed corresponding to the motor's rotational speed, based on the driving force generated by the motor. The drive switch is configured to be manually operated by the user to drive the motor. The selection switch is configured to be manually operated by the user to select a first mode or a second mode. The first mode and the second mode are operating modes of the electric lubricator, where the first mode associates the operation of the drive switch with the rotational speed in a first relationship, and the second mode associates the operation of the drive switch with the rotational speed in a second relationship different from the first relationship. The speed range in the first relationship is wider than the speed range in the second relationship. In the speed range, the rotational speed changes according to the operation amount. The control circuit is configured to control the motor via the drive circuit based on the actual amount operated by the manually operated drive switch and the first or second mode selected via the selection switch.

[0007] One aspect of the electric lubricator of this disclosure has two operating modes in which the correspondence between the amount of operation of the drive switch and the motor rotation speed differs. The user can select one of the two operating modes, thus increasing the degree of freedom in adjusting the operation of the electric lubricator. In the first mode, the user can finely adjust the motor rotation speed according to the amount of operation of the drive switch. Therefore, the convenience of the electric lubricator is improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the electric lubricator according to the first embodiment. [Figure 2] This is a central vertical cross-sectional view of the electric lubricator according to the first embodiment. [Figure 3] This is a plan view of the control panel of the electric lubricator according to the first embodiment. [Figure 4]This figure shows the electrical configuration of the electric lubricator according to the first embodiment. [Figure 5] This figure shows the functional configuration of the control circuit according to the first embodiment. [Figure 6] This figure shows the target rotational speed, actual rotational speed, motor current, and plunger stroke of the motor of the electric lubricator according to the first embodiment during acceleration. [Figure 7] This figure shows the target rotational speed, actual rotational speed, motor current, and plunger stroke of the motor of the electric lubricator according to the first embodiment during deceleration. [Figure 8] This figure shows the discharge speed (motor rotation speed) as a function of the trigger pull amount in the first mode of the electric lubricator according to the first embodiment. [Figure 9] This figure shows the discharge speed (motor rotation speed) as a function of the trigger pull amount in the second mode of the electric lubricator according to the first embodiment. [Figure 10] This flowchart shows the main process executed by the control circuit according to the first embodiment. [Figure 11] This flowchart shows the rotation speed setting process performed by the control circuit according to the first embodiment. [Figure 12] This flowchart shows the shutdown process in the first mode executed by the control circuit according to the first embodiment. [Figure 13] This is a flowchart showing the shutdown process in the second mode executed by the control circuit according to the first embodiment. [Figure 14] This flowchart shows the in-operation processing in the first mode executed by the control circuit according to the first embodiment. [Figure 15] This flowchart shows the in-operation processing in the second mode executed by the control circuit according to the first embodiment. [Figure 16] This figure shows the discharge speed (motor rotation speed) as a function of the trigger pull amount in the second mode according to the second embodiment. [Figure 17] This flowchart shows the rotation speed setting process performed by the control circuit according to the second embodiment. [Figure 18] It is a diagram showing the discharge speed (motor rotation speed) with respect to the trigger pull amount in the second mode according to the third embodiment. [Figure 19] It is a flowchart showing the rotation speed setting process executed by the control circuit according to the third embodiment. [Figure 20] It is a flowchart showing the main process executed by the control circuit according to the fourth embodiment. [Figure 21] It is a flowchart showing the continuation determination process executed by the control circuit according to the fourth embodiment.

Embodiments for Carrying Out the Invention

[0009] [Summary of Embodiments] An embodiment may provide an electric oil injector (or an electric oil syringe, or an electric grease gun) having at least any one of the following: · Feature 1: A motor configured to generate a driving force; · Feature 2: A drive circuit configured to drive the motor; · Feature 3: A pump having a discharge port configured to discharge a lubricant, and discharging the lubricant from the discharge port at a speed corresponding to the rotation speed of the motor by the driving force generated by the motor; · Feature 4: A drive switch configured to be manually operated by a user to drive the motor; · Feature 5: A selection switch configured to be manually operated by a user to select the first mode or the second mode; · Feature 6: The first mode and the second mode are operation modes of the electric oil injector; · Feature 7: The first mode associates the operation amount of the drive switch with the rotation speed in a first relationship; · Feature 8: The second mode associates the operation amount of the drive switch with the rotation speed in a second relationship different from the first relationship; · Feature 9: The speed change range in the first relationship is wider than the speed change range in the second relationship; · Feature 10: In the speed change range, the rotation speed changes according to the operation amount. Feature 11: The control circuit is configured to control the motor via the drive circuit based on the actual amount operated by the manually operated drive switch and the first or second mode selected via the selection switch.

[0010] Electric lubricators possessing at least features 1-11 have two operating modes in which the correspondence between the amount of operation of the drive switch and the motor rotation speed differs. Since the user can select one of the two operating modes, the degree of freedom in adjusting the operation of the electric lubricator increases. In the first mode, the user can finely adjust the motor rotation speed according to the amount of operation of the drive switch. Therefore, the convenience of the electric lubricator is improved.

[0011] In some embodiments, in addition to or instead of at least one of features 1 to 11, the following may be included: Feature 12: When the first mode is selected via the selection switch, the control circuit continues to drive the motor via the drive circuit while the drive switch is operated.

[0012] In the first mode of an electric lubricator that has at least features 1 to 12, the user can adjust the amount of lubricant dispensed by operating the drive switch.

[0013] In some embodiments, in addition to or instead of at least one of features 1 to 12, the following may be included: Feature 13: When the second mode is set via the selection switch, the control circuit stops the motor via the drive circuit based on the fact that a set amount of lubricant has been discharged from the discharge port.

[0014] In the second mode of an electric lubricator equipped with at least features 1-11 and 13, the user can simply operate the drive switch to dispense a set amount of lubricant from the electric lubricator and automatically stop the motor.

[0015] In some embodiments, in addition to or instead of at least one of features 1 to 13, the following may be included: Feature 14: The control circuit is configured to estimate the amount of lubricant discharged from the outlet, or to obtain the measured discharge amount, when the second mode is selected via the selection switch.

[0016] In an electric lubricator equipped with at least features 1-11 and 14, the control circuit can estimate the amount of lubricant to be dispensed, or obtain the measured amount, and stop the motor when the set amount has been dispensed.

[0017] In some embodiments, in addition to or instead of at least one of features 1 to 14, the following may be included: Feature 15: The pump has a chamber configured to contain a lubricant and communicate with the discharge port; Feature 16: The pump has a plunger configured to reciprocate within the chamber by a driving force, causing lubricant to be discharged from the outlet; Feature 17: The control circuit is configured to estimate the discharge volume based on the number of times the plunger has moved back and forth within the chamber.

[0018] In an electric lubricator having at least features 1-11 and 14-17, the control circuit can estimate the amount of lubricant discharged based on the number of reciprocating motions of the plunger.

[0019] In some embodiments, in addition to or instead of at least one of features 1 to 17, the following may be included: Feature 18: The first relationship has a variable speed range; Feature 19: The second relationship has a constant speed range and does not have a variable speed range; Feature 20: In the constant speed range, the rotational speed is constant regardless of the manipulated amount.

[0020] In the first mode of the electric lubricator, which has at least features 1-11 and 18-20, the user can adjust the motor speed by changing the amount of operation of the drive switch. In the second mode of the electric lubricator, which has at least features 1-11 and 18-20, the user can drive the motor at a constant speed by operating the drive switch. Furthermore, in the second mode, false detection or failure to detect air inclusion is suppressed because the second relationship does not have a variable speed range.

[0021] Air lock indicates a condition where air bubbles are mixed into the lubricant inside the pump. If air bubbles are present in the lubricant, the lubricant will not be discharged from the outlet even when the pump is driven by the motor. When the control circuit estimates the amount of lubricant discharged based on the number of pump cycles, false or undetected air lock reduces the accuracy of the discharge amount estimation. Air lock is detected when the motor's actual rotational speed, motor current, or motor torque does not fluctuate in response to the pump's operation. During motor acceleration and deceleration, it is more difficult to determine whether the motor's actual rotational speed, motor current, or motor torque fluctuates in response to the pump's operation compared to constant rotation. Therefore, during motor acceleration and deceleration, there is a greater possibility of false detection or oversight of air lock compared to constant rotation. In the second mode, false or undetected air lock is suppressed, allowing the control circuit to estimate the amount of lubricant discharged with high accuracy.

[0022] In some embodiments, in addition to or instead of at least one of features 1 to 20, the following may be included: Feature 21: The first relationship has a first gear shift region, which is a gear shift region; Feature 22: The second relationship has a constant speed region and a second variable speed region, which is a variable speed region; Feature 23: In the constant speed range, the rotational speed is constant regardless of the manipulated amount; Feature 24: The range in which the amount of operation changes in the second gear range is narrower than the range in which the amount of operation changes in the first gear range.

[0023] In the first mode of the electric lubricator, which has at least features 1-11 and 21-24, the user can finely adjust the motor speed by varying the amount of the drive switch operation over a wide range. In the second mode of the electric lubricator, which has at least features 1-11 and 21-24, the user can drive the motor at a constant speed by operating the drive switch, and can also finely adjust the motor speed by varying the amount of the drive switch operation over a narrow range.

[0024] In some embodiments, in addition to or instead of at least one of features 1 to 24, the following may be included: Feature 25: The first relationship has a first gear shift region, which is a gear shift region; Feature 26: The second relationship has a constant speed region and a second variable speed region, which is a variable speed region; Feature 27: In the constant speed range, the rotational speed is constant regardless of the manipulated amount; Feature 28: The range in which the rotational speed changes in the second gear range is narrower than the range in which the rotational speed changes in the first gear range.

[0025] In the first mode of the electric lubricator, which includes at least features 1-11 and 25-28, the user can finely adjust the motor speed by varying the amount of the drive switch operation over a wide range. In the second mode of the electric lubricator, which includes at least features 1-11 and 25-28, the user can operate the drive switch to drive the motor at a constant speed, and also accelerate or decelerate the motor within a range that suppresses false detection or failure to detect air in the system.

[0026] In one embodiment, the above-described features 1 to 28 may be combined in any combination. In one embodiment, any of the above-described features 1 to 28 may be excluded.

[0027] [Specific exemplary embodiments] The following exemplary embodiment provides an electric lubricator 1 shown in Figure 1. The electric lubricator 1 is an electric grease gun configured to dispense a semi-solid lubricant, more specifically grease.

[0028] For the sake of clarity, the directions in the electric lubricator 1 are defined as shown in Figure 1 and subsequent figures. Specifically, "up" (upward direction), "down" (downward direction), "right" (rightward direction), "left" (leftward direction), "forward" (forward direction), and "backward" (backward direction) are defined.

[0029] (1. First Embodiment) <1-1. Structure> <1-1-1. Mechanical configuration of an electric lubricator> As shown in Figures 1 and 2, the electric lubricator 1 includes a housing 2. The housing 2 comprises a first split housing 2a and a second split housing 2b that are joined together.

[0030] The housing 2 is provided with 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 an electric motor (hereinafter abbreviated as "motor") 20.

[0031] 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.

[0032] The electric lubricator 1 is equipped with a trigger switch 8 housed within the grip 5. The electric lubricator 1 is also equipped with a trigger 9 for the user of the electric lubricator 1 to manually operate the trigger switch 8.

[0033] 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.

[0034] 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.

[0035] 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 lubricator 1.

[0036] 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).

[0037] The rear coupling portion 7 is provided with a battery holding portion 14 at its rear end. The battery holding portion 14 is configured to allow the battery pack 15 to be detachably attached. 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. In this first embodiment, the battery pack 15 has a rated voltage of 36 volts.

[0038] 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.

[0039] 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.

[0040] In this first embodiment, the motor 20 is an inner rotor type brushless motor (more specifically, a 3-phase brushless DC motor). In another embodiment, the motor 20 may be any other type of motor (e.g., a brushed DC motor). Specifically, the motor 20 may be a 1-phase brushless DC motor, a 2-phase brushless DC motor, a 4-phase or more brushless DC motor, a brushed motor, an AC motor, or a stepping motor.

[0041] 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.

[0042] 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.

[0043] The second insulator 23B is equipped with a short-circuiting member 25. The short-circuiting member 25 is equipped with three insert-molded short-circuiting fittings 26 (Figure 2 shows only two short-circuiting fittings 26). These short-circuiting 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).

[0044] 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 5). 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.

[0045] 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.

[0046] The first to third rotational position sensors 28A to 28C (i) are arranged around the rotor 22 and (ii) detect the rotational position of the rotation axis 30, and consequently the rotational position of the rotor 22. 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.

[0047] 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. 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.

[0048] The gear housing 40 is equipped with a spindle 44 at its front end. The gear housing 40 houses a reduction mechanism 43. The reduction mechanism 43 is configured to (i) receive rotation from 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 reduction mechanism 43 may include planetary gears.

[0049] 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.

[0050] 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.

[0051] 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 is movable in the height direction along the slider guide 49.

[0052] 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.

[0053] 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.

[0054] The electric lubricator 1 includes 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The upper cylinder portion 60A is equipped with a seal ring 61A at its upper part. 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.

[0059] 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 lubricator 1.

[0060] 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 the backflow of grease from the discharge passage 66 into the chamber 63.

[0061] 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 lubricator 1 when the pressure of the grease in the discharge passage 66 exceeds a predetermined pressure.

[0062] 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 lubricator 1. When the air drain valve 67 is tightened, the chamber 63 is isolated from the outside of the electric lubricator 1. The electric lubricator 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 lubricator 1. If gas is present in the chamber 63 at this time, that gas can be released to the outside of the electric lubricator 1 via the air drain valve 67.

[0063] In the electric lubricator 1 configured as described above, when the user pulls the trigger 9, the motor 20 rotates, and consequently, the rotating shaft 30 rotates. The rotation of the rotating shaft 30 is transmitted to the spindle 44 via the reduction mechanism 43, and the crankshaft 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.

[0064] <1-1-2. Configuration of the control panel> As shown in Figure 3, 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.

[0065] Each time the first switch 71 is briefly pressed, the rotation speed (i.e., rotational speed) of the motor 20 is sequentially switched to one of several levels (for example, four levels). The motor 20 rotates at a rotation speed corresponding to the level set by the first switch 71.

[0066] 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.

[0067] The control panel 70 includes a first display screen 74. The first display screen 74 displays the set rotation speed level (for example, one of "1" to "4"). 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).

[0068] The control panel 70 is equipped with 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 lubricator 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). Hereinafter, the continuous discharge mode will be referred to as the first mode, and the automatic discharge mode as the second 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 first mode and the second mode.

[0069] In the first mode, while the trigger 9 is pulled, the motor 20 continues to rotate at the set target rotation speed. In the second mode, the motor 20 starts rotating when the trigger 9 is pulled. After rotation begins, once the plunger 50 (in other words, the slider 48) has moved back and forth a set number of times (in other words, once the set amount of grease has been dispensed), the motor 20 automatically stops, even if the trigger 9 is still being pulled. The set number of back and forth can be set to any value by the user.

[0070] The control panel 70 is equipped with a setting count display screen 75. The setting count display screen 75 is equipped with the aforementioned second display screen 75A and third display screen 75B. When the first mode is set as the operating mode, the setting count display screen 75 displays symbols indicating the first mode. The setting count display screen 75 shows the set number of round trips when the second mode is set as the operating mode.

[0071] In this first embodiment, in the second mode, any set number of reciprocations can be set, up to a predetermined maximum set number of 99 or less. Depending on the structure of the pump 60, the amount of grease discharged from the discharge port 66A in one cycle is predetermined. Therefore, setting the set number of reciprocations by the user is equivalent to setting the amount of grease discharged. The user can set the set number of reciprocations to any value by operating the second switch 72 or the third switch 73. Specifically, in the second mode, each time the second switch 72 is pressed, the set number of reciprocations increases by one, and the increased set number of reciprocations is displayed on the set number display screen 75. Conversely, in the second mode, each time the third switch 73 is pressed, the set number of reciprocations decreases by one, and the decreased set number of reciprocations is displayed on the set number display screen 75. The maximum set number can be determined in any way and may be set to 100 or more. In another embodiment, in the second mode, the electric lubricator 1 may be configured so that the discharge amount can be set via the operation panel 70.

[0072] <1-1-3. Electrical configuration of an electric lubricator> Referring to Figure 4, the electrical configuration of the electric lubricator 1 will be described. The electric lubricator 1 includes a control circuit board 18 with a ground. The electric lubricator 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 lubricator 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.

[0073] The electric lubricator 1 is equipped with 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 the power supply voltage) Vc based on the rated voltage of the battery pack 15.

[0074] The electric lubricator 1 is equipped with 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. Non-volatile memory includes, for example, EEPROM, 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.

[0075] 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.

[0076] The electric lubricator 1 includes a drive circuit 82 configured to drive a motor 20. In this first embodiment, the drive circuit 82 is located on a control circuit board 18. The drive circuit 82 is a three-phase full-bridge circuit, but is not limited to a three-phase full-bridge circuit. In another embodiment, it may be a one-phase, two-phase, or four-phase or more full-bridge circuit, or a half-bridge circuit. The drive circuit 82 includes first to third semiconductor switches Q1 to Q3 located on the high side and fourth to sixth semiconductor switches Q4 to Q6 located on the low side. The first to third semiconductor switches Q1 to Q3 are connected to the power line Lp and the lead wires 27 of the motor 20, and function as so-called high-side switches. The fourth to sixth semiconductor switches Q4 to Q6 are connected to the lead wires 27 and ground, and function as so-called low-side switches.

[0077] The first to sixth semiconductor 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 are pulse width modulation (PWM) signals. The first to sixth semiconductor switches Q1 to Q6 are semiconductor switches. Examples of semiconductor switches include metal-oxide-semiconductor field-effect transistors (MOSFETs), junction field-effect transistors (JFETs), bipolar transistors, insulated-gate bipolar transistors (IGBTs), solid-state relays (SSRs), and thyristors.

[0078] The electric lubricator 1 includes a sliding resistor 81 having a lever 81A. The lever 81A has a displaceable first end and a second end connected to a control circuit 80. The sliding resistor 81 has a resistance value that changes depending on the position of the first end of the lever 81A. The second end of the lever 81A outputs a signal to the control circuit 80 having a voltage of a magnitude corresponding to the resistance value. The first end of the lever 81A is displaced according to the position of the trigger 9 in a range from the initial position to the maximum position. For example, the resistance value of the sliding resistor 81 is minimum when the trigger 9 is in the initial position and increases as the trigger 9 approaches the maximum position from the initial position.

[0079] The electric lubricator 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 a power supply voltage Vc from the power supply circuit 84. The first pull-up resistor R1 has a first terminal of the trigger switch 8 and a second terminal connected to the control circuit 80. The second pull-up resistor R2 has a first terminal of the first switch 71 and a second terminal connected to the control circuit 80. The third pull-up resistor R3 has a first terminal of the second switch 72 and a second terminal connected to the control circuit 80. The fourth pull-up resistor R4 has a first terminal of 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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 sinusoidal signals, and their respective voltages invert 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.

[0084] In another embodiment, the sensor circuit board 28 may be configured to output a rotation detection signal (e.g., a pulse signal) to the control circuit 80 each time the rotor 22 rotates 60 degrees in electrical angle, instead of the first to third rotation signals.

[0085] <1-1-4. Functional configuration of an electric lubricator> Referring to Figure 5, the functions of the control circuit 80 will be described. The control circuit 80 includes the functions of a trigger pull amount detection unit 77, a switch detection unit 78, a reciprocation count setting unit 83, a reciprocation count calculation unit 79, a display control unit 85, a rotation speed setting unit 86, an operation mode setting unit 87, a timing unit 88, a reciprocation 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.

[0086] 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 trigger pull amount detection unit 77, the switch detection unit 78, the reciprocation count setting unit 83, the reciprocation count calculation unit 79, the display control unit 85, the rotation speed setting unit 86, the operation mode setting unit 87, the timing unit 88, the reciprocation determination unit 89, the air lock detection unit 90, the operation control unit 91, and the motor drive control unit 92.

[0087] The trigger pull amount detection unit 77 detects the actual pull amount of the trigger 9 based on the voltage input from the sliding resistor 81. Specifically, the trigger pull amount detection unit 77 detects zero if the voltage corresponds to the initial position of the trigger 9. The trigger pull amount detection unit 77 detects the maximum amount if the voltage corresponds to the maximum position of the trigger 9. The trigger pull amount detection unit 77 detects an actual pull amount between zero and the maximum value if the voltage corresponds to an intermediate position of the trigger 9. The intermediate position is between the initial position and the maximum position. The trigger pull amount detection unit 77 outputs the detected actual pull amount to the rotation speed setting unit 86.

[0088] The switch detection unit 78 detects the change from off to on and from on to off of the trigger switch 8, the first switch 71, the second switch 72, and the third switch 73. The switch detection unit 78 outputs the first signal and the second signal to the operation control unit 91, and outputs the third signal and the fourth signal to the operation mode setting unit 87. The switch detection unit 78 also outputs the first signal to the round trip count calculation unit 79. The first signal indicates that the trigger switch 8 has changed from off to on, and the second signal indicates that the trigger switch 8 has changed from on to off. The third signal indicates that the first switch 71 has changed from off to on. The fourth signal indicates that the second switch 72 and the third switch 73 have changed from off to on almost simultaneously.

[0089] Furthermore, after detecting that the second switch 72 and the third switch 73 have changed from on to off almost simultaneously, the switch detection unit 78 detects the number of times N the second switch 72 has changed from off to on within a predetermined period. Also, after detecting that the second switch 72 and the third switch 73 have changed from on to off almost simultaneously, the switch detection unit 78 detects the number of times M the third switch 73 has changed from off to on within a predetermined period. The switch detection unit 78 then outputs the detected number N and number M to the round trip count setting unit 83.

[0090] The operation mode setting unit 87 sets the rotation speed level of the motor 20 according to the input third signal. For example, if the rotation speed levels are set to levels 1 to 4, the operation mode setting unit 87 changes the rotation speed level in the order of level 1 → level 2 → level 3 → level 4 each time the third signal is input.

[0091] Furthermore, the operation mode setting unit 87 sets the operation mode of the electric lubricator 1 to either the first mode or the second mode according to the input fourth signal. Specifically, each time the fourth signal is input, the operation mode setting unit 87 switches the operation mode from the first mode to the second mode, or from the second mode to the first mode. The operation mode setting unit 87 outputs the set rotation speed level and operation mode to the operation control unit 91. The operation mode setting unit 87 outputs the set operation mode to the rotation speed setting unit 86. The operation mode setting unit 87 also outputs the set rotation speed level to the display control unit 85 (arrow omitted in Figure 5).

[0092] The rotation speed setting unit 86 sets the target rotation speed of the motor 20 based on the input actual pull amount and operating mode. The actual rotation 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. Specifically, when the operating mode is the first mode, the rotation speed setting unit 86 sets the target rotation speed based on the input actual pull amount and the first relationship shown in Figure 8. The first relationship associates the pull amount of the trigger 9 with the rotation speed of the motor 20. That is, the first relationship corresponds to a function of rotation speed with respect to the pull amount. The rotation speed setting unit 86 sets the rotation speed associated with the actual pull amount in the first relationship to the target rotation speed.

[0093] Furthermore, when the operating mode is the second mode, the rotation speed setting unit 86 sets the target rotation speed based on the input actual pull amount and the second relationship shown in Figure 9. The second relationship is different from the first relationship, and it associates the pull amount of the trigger 9 with the rotation speed of the motor 20. That is, the second relationship is a function of rotation speed with respect to pull amount, and corresponds to a different function from the first relationship. The rotation speed setting unit 86 sets the rotation speed associated with the actual pull amount in the second relationship as the target rotation speed. The rotation speed setting unit 86 outputs the set target rotation speed to the operation control unit 91 and the air entrainment detection unit 90. Details of how the rotation speed setting unit 86 sets the target rotation speed will be described later.

[0094] The timing unit 88 counts every clock cycle. For example, if the clock frequency is 1 Hz, the timing unit 88 counts every second and outputs the count value to the operation control unit 91.

[0095] The round trip count setting unit 83 calculates the set number of round trips for the plunger 50 based on the input number N and number M when the second mode is set as the operating mode. Specifically, the round trip count setting unit 83 calculates N × 10 + M times as the set number of round trips. The round trip count setting unit 83 outputs the set number of round trips to the round trip count calculation unit 79.

[0096] 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 reduction mechanism 43, the reciprocating determination unit 89 determines whether the plunger 50 has made one reciprocating motion. If the reciprocating determination unit 89 determines that the plunger 50 has made one reciprocating motion, it outputs a reciprocating determination signal to the reciprocating count calculation unit 79 and the air entrapment detection unit 90.

[0097] The air lock detection unit 90 detects air lock in the grease. Air lock indicates that air bubbles are mixed into the grease in the chamber 63. If air bubbles are present in the chamber 63, grease will not be discharged from the discharge port 66A even when the plunger 50 moves back and forth. Therefore, if the number of reciprocations of the plunger 50 is calculated without considering air lock, the number of reciprocations of the plunger 50 will not match the number of grease discharges. Consequently, the number of reciprocations of the plunger 50 will not correspond to the amount of grease discharged. The air lock detection unit 90 detects air lock in order to make the number of reciprocations of the plunger 50 correspond to the amount of grease discharged.

[0098] A load corresponding to the amount of grease discharged is applied to the motor 20. Therefore, when grease is discharged from the discharge port 66A, the actual rotational speed of the motor 20, the motor current flowing to the motor 20, and the motor torque fluctuate in accordance with one reciprocation of the plunger 50 (i.e., one discharge of grease). Specifically, the actual rotational speed becomes minimum in accordance with one reciprocation of the plunger 50. Also, the motor current and motor torque become maximum in accordance with one reciprocation of the plunger. On the other hand, when grease is not discharged from the discharge port 66A, the actual rotational speed, motor current, and motor torque do not fluctuate in accordance with one reciprocation of the plunger 50. Therefore, when the air lock detection unit 90 receives a reciprocation determination signal from the reciprocation determination unit 89, it detects air lock based on the absence of a minimum actual rotational speed or a maximum motor current or motor torque corresponding to the reciprocation determination signal. When the air lock detection unit 90 detects air lock, it outputs an air lock detection signal to the reciprocation count calculation unit 79, the operation control unit 91, and the display control unit 85.

[0099] As shown in Figure 6, the motor current reaches a maximum during acceleration of the motor 20. Therefore, during acceleration of the motor 20, there is a greater possibility of overlooking the air-locked state of the electric lubricator 1 compared to when the motor 20 is rotating at a constant speed. Also, as shown in Figure 7, the amplitude of the motor current decreases during deceleration of the motor 20. Therefore, during deceleration of the motor 20, even if the motor current fluctuates in accordance with one reciprocation of the plunger 50, there is a possibility that the fluctuation in the motor current will not be detected. In other words, during deceleration of the motor 20, there is a greater possibility of falsely detecting the air-locked state of the electric lubricator 1 compared to when the motor 20 is rotating at a constant speed.

[0100] Therefore, if the air lock detection unit 90 detects that the motor 20 is accelerating based on the target rotation speed input from the rotation speed setting unit 86, it does not need to perform the air lock detection process. Also, if the air lock detection unit 90 detects that the motor 20 is decelerating based on the input target rotation speed, it does not need to perform the air lock detection process.

[0101] The reciprocating count calculation unit 79 updates the reciprocating count of the plunger 50 by increasing it by "1" each time it receives a reciprocating determination from the reciprocating determination unit 89. The reciprocating count calculation unit 79 does not update the reciprocating count even if it receives a reciprocating determination signal while it is receiving an air lock signal from the air lock detection unit 90. The reciprocating count calculation unit 79 updates the reciprocating count of the plunger 50 by increasing it by "1" when it has not received an air lock detection signal from the air lock detection unit 90 and has received a reciprocating determination signal from the reciprocating determination unit 89. The reciprocating count of the plunger 50 corresponds to the amount of grease discharged. Therefore, calculating the reciprocating count of the plunger 50 is equivalent to estimating the amount of grease discharged.

[0102] In another embodiment, the electric lubricator 1 may be equipped with a fluid sensor near the discharge port 66A to measure the amount of grease discharged from the discharge port 66A. Instead of calculating the number of reciprocations of the plunger 50, the control circuit 80 may acquire the measured discharge amount. Alternatively, the electric lubricator 1 may be equipped with a sensor near the plunger 50 to measure the movement of the plunger 50 and measure the number of reciprocations of the plunger 50. Instead of calculating the number of reciprocations of the plunger 50, the control circuit 80 may acquire the measured number of reciprocations (i.e., the discharge amount).

[0103] Furthermore, immediately after the trigger switch 8 changes from off to on (for example, within a few seconds), the plunger 50 may move before the grease is dispensed. Therefore, the round trip count calculation unit 79 does not need to update the round trip count even if it receives a round trip determination signal within a set time (for example, a few seconds) after receiving the first signal from the switch detection unit 78. Each time the round trip count is updated, the round trip count calculation unit 79 outputs the updated round trip count to the display control unit 85. In addition, the round trip count calculation unit 79 outputs the count difference to the operation control unit 91. The count difference is the difference between the input set round trip count and the current round trip count.

[0104] The motion control unit 91 receives the rotational speed level and the target rotational speed and updates the target rotational speed based on the rotational speed level. Specifically, if the rotational speed level is at the reference level (for example, the first level), the motion control unit 91 outputs the input target rotational speed to the motor drive control unit 92 without updating it. If the rotational speed level is other than the reference level, the motion control unit 91 multiplies the target rotational speed by a level coefficient and updates the target rotational speed. Then, the motion control unit 91 outputs the updated target rotational speed to the motor drive control unit 92. The level coefficient is larger the higher the rotational speed level.

[0105] The operation control unit 91 receives either the first or second signal and determines whether the trigger 9 is on or off. If the input operation mode is the first mode and the trigger 9 is on, the operation control unit 91 outputs a drive command to the motor drive control unit 92. If the input operation mode is either the first mode or the second mode and the trigger 9 is off, the operation control unit 91 outputs a stop command to the motor drive control unit 92.

[0106] The operation control unit 91 outputs a drive command to the motor drive control unit 92 if the input operation mode is the second mode, the trigger 9 is ON, and the input count difference is 1 or more. The operation control unit 91 outputs a stop command to the motor drive control unit 92 if the input operation mode is the second mode, the trigger 9 is ON, and the input count difference is less than 1.

[0107] Furthermore, in the fourth embodiment described later, the operation control unit 91 outputs a stop command to the motor drive control unit 92 if the air lock condition persists for a predetermined time, based on the count value input from the timing unit 88 and the air lock detection signal input from the air lock detection unit 90. In this embodiment, the operation control unit 91 does not need to receive a count value from the timing unit 88, nor does it need to receive an air lock detection signal from the air lock detection unit 90.

[0108] The motor drive control unit 92 receives the first to third rotation signals from the first to third rotation position sensors 28A to 28C and calculates the actual rotational speed of the motor 20. When the motor drive control unit 92 receives a drive command from the operation control unit 91, it generates the first to sixth drive control signals for the first to sixth semiconductor switches Q1 to Q6 based on the difference between the target rotational speed and the actual rotational speed, and outputs the generated first to sixth drive control signals to the drive circuit 82. Also, when the motor drive control unit 92 receives a stop command from the operation control unit 91, it generates the first to sixth stop signals for the first to sixth semiconductor switches Q1 to Q6, and outputs the generated first to sixth stop signals to the drive circuit 82.

[0109] 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 current number of reciprocations input from the number of reciprocations calculation unit 79 on the second display screen 75A and the third display screen 75B. In addition, when an air lock detection signal is input, the display control unit 85 notifies the user of the air lock and prompts them to bleed the air. Specifically, it notifies the user of the air lock by flashing the second display screen 75A and the third display screen 75B. Alternatively, the display control unit 85 may notify the user of the air lock by displaying a preset number, symbol, character, etc. on the second display screen 75A and the third display screen 75B.

[0110] In another embodiment, the electric lubricator 1 may be equipped with an indicator, for example, a light-emitting diode. When air is detected in the system, the control circuit 80 may notify the system of air inclusion by lighting or flashing the indicator, instead of flashing or displaying symbols on the second display screen 75A and the third display screen 75B. Furthermore, in another embodiment, the electric lubricator 1 may be equipped with a buzzer. When air is detected in the system, the control circuit 80 may notify the system of air inclusion by outputting a warning sound from the buzzer, instead of flashing or displaying symbols on the second display screen 75A and the third display screen 75B.

[0111] <1-2. Setting the target rotation speed> Referring to Figure 8, the setting of the target rotational speed when the operating mode is the first mode will be explained. In Figure 8, the first pull amount X1 corresponds to the minimum position of the trigger 9. The second pull amount X2 corresponds to the maximum position of the trigger 9. The third pull amount X3a corresponds to the position between the minimum and maximum positions. In the first relationship, the first pull amount X1 is associated with the minimum rotational speed ωmin. In the first relationship, the range from the third pull amount X3a to the second pull amount X2 corresponds to the maximum speed ωmax.

[0112] In the range from the first pull amount X1 to the third pull amount X3a, the rotational speed increases in proportion to the increase in pull amount. In the range from the third pull amount X3a to the second pull amount X2, the rotational speed remains constant regardless of the pull amount. Therefore, the first relationship has a first variable speed region Rv1 and a first constant speed region Rc1. The first variable speed region Rv1 is a variable speed region in which the rotational speed changes according to the pull amount, and corresponds to the range from the first pull amount X1 to the third pull amount X3a. The first constant speed region Rc1 is a constant speed region in which the rotational speed remains constant regardless of the pull amount, and corresponds to the range from the third pull amount X3a to the second pull amount X2. In another embodiment, the first relationship may have a first variable speed region Rv1 but not a first constant speed region Rc1.

[0113] The first variable speed range Rv1 is wider than the first constant speed range Rc1. In the first mode, the user continues to pull the trigger 9 until the desired amount of grease is dispensed. The control circuit 80 continues to drive the motor 20 while the trigger 9 is pulled. There may be various requirements regarding the dispensing speed. For example, there may be a desire to dispense the desired amount of grease in a short period of time. Also, there may be a desire to dispense grease at high speed at the start of dispensing, and then at a low speed when the amount of grease dispensed approaches the desired amount. Therefore, in the first mode, it is desirable to be able to finely adjust the dispensing speed according to the amount the trigger is pulled. Thus, the first relationship has a wide variable speed range.

[0114] Referring to Figure 9, the setting of the target rotational speed when the operating mode is the second mode will be explained. In the second relationship, the range from the first pull amount X1 to the second pull amount X2 corresponds to the maximum speed ωmax. The second relationship has a second constant speed region Rc2 and does not have a variable speed region. The second constant speed region Rc2 corresponds to the range from the first pull amount X1 to the second pull amount X2 and is wider than the first constant speed region Rc1.

[0115] In the second mode, the user inputs the set number of reciprocations of the plunger 50 according to the desired amount of grease. The user then pulls the trigger 9, expecting the desired amount of grease to be dispensed automatically (i.e., without user adjustment). Therefore, in the second mode, there is little demand for adjustable dispensing speed, and it is desirable that the desired amount of grease be dispensed. In other words, it is desirable to suppress missed air locks and false detections and to match the number of grease dispensing reciprocations to the set number of reciprocations. As mentioned above, when the motor 20 is accelerating, the possibility of missing air locks increases compared to when it is rotating at a constant speed. Also, when the motor 20 is decelerating, the possibility of false detection of air locks increases compared to when it is rotating at a constant speed. Therefore, the second relationship does not have a variable speed range in which the accuracy of air lock detection decreases.

[0116] <1-3. Processing> <1-3-1. Main Processing> Referring to the flowchart in Figure 10, the main processing performed by the control circuit 80 according to the first embodiment will be described. The control circuit 80 repeatedly performs the main processing at predetermined intervals.

[0117] In S10, the control circuit 80 determines whether the trigger switch 8 is ON. If the control circuit 80 determines that the trigger switch 8 is ON (S10: YES), it proceeds to process S60. If the control circuit 80 determines that the trigger switch 8 is OFF (S10: NO), it proceeds to process S20.

[0118] In S20, the control circuit 80 outputs the first to sixth stop signals to the drive circuit 82, stopping the motor 20. After that, the control circuit 80 proceeds to the process in S30. In S30, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S30: YES), it proceeds to process S50. If the control circuit 80 determines that the first mode is set as the operating mode (S30: NO), it proceeds to process S40.

[0119] In S40, the control circuit 80 executes the first stop processing and proceeds to the processing in S100. Details of the first stop processing will be described later. In S50, the control circuit 80 executes the second stop processing and proceeds to the processing in S100. Details of the second stop processing will be described later.

[0120] In S60, the control circuit 80 performs the target rotation speed setting process and sets the target rotation speed of the motor 20. After that, the control circuit 80 proceeds to the process in S70. Details of the target rotation speed setting process will be described later.

[0121] In S70, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S70: YES), it proceeds to process S90. If the control circuit 80 determines that the first mode is set as the operating mode (S70: NO), it proceeds to process S80.

[0122] In S80, the control circuit 80 executes the first in-operation processing and proceeds to the processing in S100. Details of the first in-operation processing will be described later. In S90, the control circuit 80 executes the second in-operation processing and proceeds to the processing in S100. Details of the second in-operation processing will be described later.

[0123] In S100, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S100: YES), it proceeds to process S120. If the control circuit 80 determines that the first mode is set as the operating mode (S100: NO), it proceeds to process S110.

[0124] In S110, the control circuit 80 displays a symbol or the like on the setting count display screen 75 to indicate that it is in the first mode, thereby notifying the user that the first mode is set as the operating mode. After that, the control circuit 80 returns to the process in S10.

[0125] In S120, the control circuit 80 calculates the current number of round trips of the plunger 50 and calculates the difference between the set number of round trips and the current number of round trips. After that, the control circuit 80 proceeds to the process in S130.

[0126] In S130, the control circuit 80 determines whether the difference in the number of cycles calculated in S120 is 0 or not. That is, the control circuit 80 determines whether the amount of grease dispensed, as set by the user, has been dispensed. If the control circuit 80 determines that the difference in the number of cycles is greater than 0 (S130: NO), it proceeds to the process in S140. If the control circuit 80 determines that the difference in the number of cycles is 0 (S130: YES), it proceeds to the process in S150.

[0127] In S140, the control circuit 80 displays the current number of strokes of the plunger 50 on the set count display screen 75. This allows the user to recognize that the grease dispensing is not yet complete. The control circuit 80 then returns to the process in S10.

[0128] In S150, the control circuit 80 displays the set number of cycles on the set cycle display screen 75. This allows the user to recognize that the grease dispensing is complete. After that, the control circuit 80 returns to the process in S10.

[0129] <1-3-2. Setting the target rotation speed> Referring to the flowchart in Figure 11, the target rotational speed setting process performed by the control circuit 80 in S60 will be explained.

[0130] In S200, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S200: YES), it proceeds to the process in S230. If the control circuit 80 determines that the first mode is set as the operating mode (S200: NO), it proceeds to the process in S210.

[0131] In S210, the control circuit 80 calculates the pull ratio Pa. The pull ratio Pa is a value between 0 and 100%. As shown in Figure 8, the control circuit 80 assigns the pull ratio Pa of 0 to 100% to the first speed change region Rv1 and the pull ratio Pa = 100% to the first constant speed region Rc1. That is, the control circuit 80 calculates the pull ratio Pa = 0% for the first pull amount X1 and the pull ratio Pa = 100% for the third pull amount X3a. When the actual pull amount is between the first pull amount X1 and the third pull amount X3a, the control circuit 80 increases the pull ratio Pa in proportion to the increase in the actual pull amount. When the actual pull amount is between the third pull amount X3a and the second pull amount X2, the control circuit 80 calculates the pull ratio Pa = 100%.

[0132] In S220, the control circuit 80 calculates the target rotational speed using the displacement ratio Pa calculated in S210, and then terminates this process. Specifically, the control circuit 80 calculates the target rotational speed based on the formula: Target rotational speed = (ωmax - ωmin) × Pa + ωmin.

[0133] In S230, the control circuit 80 sets the maximum speed ωmax to the target rotational speed and terminates this process.

[0134] <1-3-3. First Stop Processing> Referring to the flowchart in Figure 12, the first stop processing performed by the control circuit 80 in S40 will be described.

[0135] In S300, the control circuit 80 determines whether the user has pressed the second switch 72 and the third switch 73 simultaneously to request a change in the operating mode. If the control circuit 80 determines that a change in the operating mode has been requested (S300: YES), it proceeds to the process in S310. If the control circuit 80 determines that a change in the operating mode has not been requested (S300: NO), it terminates this process.

[0136] In S310, the control circuit 80 changes the operating mode from the first mode to the second mode and terminates this process. Note that the control circuit 80 does not change the operating mode even if the second switch 72 and the third switch 73 are pressed simultaneously when the trigger switch 8 is ON. The control circuit 80 changes the operating mode only when the trigger switch 8 is OFF.

[0137] <1-3-4. Second Stop Processing> Referring to the flowchart in Figure 13, the second stop process executed by the control circuit 80 in S50 will be described.

[0138] In S400, the control circuit 80 determines whether the count difference calculated in S120 of the previous processing cycle is 0 or not. If the control circuit 80 determines that the count difference is 0 (S400: YES), it proceeds to the process in S410. If the control circuit 80 determines that the count difference is greater than 0 (S400: NO), it skips the process in S410 and proceeds to the process in S420.

[0139] In S410, the control circuit 80 resets the current number of round trips of the plunger 50 (i.e., sets it to 0) because the dispensing of the set amount has been completed. Then, the process proceeds to S420.

[0140] In S420, the control circuit 80 determines whether the user has pressed the second switch 72 and the third switch 73 simultaneously to request a change in the operating mode. If the control circuit 80 determines that a change in the operating mode has been requested (S420: YES), it proceeds to the process in S430. If the control circuit 80 determines that a change in the operating mode has not been requested (S420: NO), it proceeds to the process in S450.

[0141] In S430, the control circuit 80 resets the current number of round trips of the plunger 50 in order to switch the operating mode. After that, the control circuit 80 proceeds to the process in S440. In S440, the control circuit 80 changes the operating mode from the second mode to the first mode and terminates this process.

[0142] In S450, the control circuit 80 determines whether the user has pressed the second switch 72 and / or the third switch 73 to request a change in the set number of round trips. If the control circuit 80 determines that a change in the set number of round trips has been requested (S450: YES), it proceeds to the process in S460. If the control circuit 80 determines that a change in the set number of round trips has not been requested (S450: NO), it terminates this process.

[0143] In S460, the control circuit 80 resets the current number of round trips of the plunger 50 in order to change the set number of round trips, and then proceeds to the process in S470. In S470, the control circuit 80 changes the set number of round trips based on the number of times the second switch 72 and / or the third switch 73 are pressed. After that, the control circuit 80 terminates this process.

[0144] <1-3-5. First Operation Processing> Referring to the flowchart in Figure 14, the first in-operation processing performed by the control circuit 80 in S80 will be described.

[0145] In S500, the control circuit 80 drives the motor 20 based on the target rotational speed set in S60. That is, the control circuit 80 controls the rotation of the motor 20 so that its actual rotational speed is maintained at the target rotational speed. After that, the control circuit 80 proceeds to the process in S510.

[0146] In S510, the control circuit 80 determines whether the motor 20 is accelerating or decelerating. Specifically, it determines whether the motor 20 is accelerating or decelerating based on the target rotational speed or actual rotational speed in the most recent predetermined number of processing cycles. If the control circuit 80 determines that the motor 20 is accelerating or decelerating (S510: YES), it proceeds to process S530. If the control circuit 80 determines that the motor 20 is rotating at a constant speed (S510: NO), it proceeds to process S520.

[0147] In S520, the control circuit 80 performs air lock detection processing based on the actual rotational speed, motor current, or motor torque. If the control circuit 80 detects air lock, it sets the air lock status to "Detected". If the control circuit 80 does not detect air lock, it sets the air lock status to "Not Detected". After that, the control circuit 80 proceeds to the processing in S540.

[0148] In S530, the control circuit 80 sets the air lock status to "not detected" and proceeds to the process in S540. As mentioned above, the accuracy of air lock detection decreases during acceleration and deceleration of the motor 20. Therefore, the control circuit 80 does not perform the air lock detection process during acceleration or deceleration of the motor 20.

[0149] In S540, the control circuit 80 calculates the amount of movement of the plunger 50 from a predetermined position based on the first to third rotation signals and the reduction ratio of the reduction mechanism 43. The predetermined position is the position of the plunger 50 when it was determined that the plunger 50 had completed one round trip in the previous operation. After that, the control circuit 80 proceeds to the process in S550.

[0150] In S550, the control circuit 80 determines whether the plunger 50 has completed one round trip based on the amount of movement calculated in S540. If the control circuit 80 determines that the plunger 50 has completed one round trip (S550: YES), it proceeds to the process in S560. If the control circuit 80 determines that the plunger 50 has not completed one round trip (S550: NO), it terminates this process.

[0151] In S560, the control circuit 80 determines whether "detected" is set to the air lock condition. If the control circuit 80 determines that "detected" is set to the air lock condition (S560: YES), it proceeds to process S570. If the control circuit 80 determines that "not detected" is set to the air lock condition (S560: NO), it proceeds to process S580.

[0152] In S570, the control circuit 80 starts announcing air lock and terminates this process. Specifically, the control circuit 80 blinks the symbols indicating the first mode displayed on the second display screen 75A and the third display screen 75B, and terminates this process.

[0153] In S580, the control circuit 80 terminates the air lock notification and ends this process. Specifically, the control circuit 80 lights up the symbols indicating the first mode displayed on the second display screen 75A and the third display screen 75B, and ends this process.

[0154] <1-3-6. Second Operation Processing> Referring to the flowchart in Figure 15, the second in-operation processing performed by the control circuit 80 in S90 will be explained.

[0155] In S600, the control circuit 80 determines whether the count difference calculated in S120 of the previous processing cycle is greater than 0. If the control circuit 80 determines that the count difference is greater than 0 (S600: YES), it proceeds to process S620. If the control circuit 80 determines that the count difference is 0 (S600: NO), it proceeds to process S610.

[0156] In S610, the control circuit 80, having completed the discharge of the set amount, outputs the first to sixth stop signals to the drive circuit 82 to stop the motor 20. After that, the control circuit 80 terminates this process.

[0157] In S620-S680, the control circuit 80 performs the same processing as in S500-S560. In S680, if the control circuit 80 determines that "detected" is set to air lock status (S680:YES), it proceeds to process S690. If the control circuit 80 determines that "not detected" is set to air lock status (S680:NO), it proceeds to process S700.

[0158] In S690, the control circuit 80 performs the same processing as in S570 and terminates this process. In S700, the control circuit 80 increases the current number of round trips of the plunger 50 by "1" and proceeds to the processing in S710.

[0159] In S710, the control circuit 80 performs the same processing as in S580 and terminates this process.

[0160] <1-4. Effects> The first embodiment described in detail above provides the following effects. (1) The electric lubricator 1 has two operating modes in which the correspondence between the amount of trigger operation 9 and the rotational speed of the motor 20 is different. The user can select one of the two operating modes, which increases the degree of freedom in adjusting the operation of the electric lubricator. Therefore, the convenience of the electric lubricator is improved.

[0161] (2) The first relationship of the first mode has a first speed range Rv1, which allows the user to finely adjust the target rotational speed of the motor 20 by operating the trigger 9. (3) In the second mode, since there is no variable speed range, the user can operate the trigger 9 to drive the motor 20 at a constant target rotational speed. Furthermore, in the second mode, since the second relationship does not have a variable speed range, false detection or failure to detect air inclusion is suppressed. As a result, the control circuit can estimate the amount of grease discharged with high accuracy in the second mode.

[0162] (4) In the second mode, the user can operate the trigger 9 to turn on the trigger switch 8, which will cause the electric lubricator 1 to dispense a set amount of grease and automatically stop the motor 20.

[0163] (5) In the first mode, the user can adjust the amount of grease dispensed by operating the trigger 9. (6) The control circuit 80 estimates the amount of grease to be dispensed or obtains the measured amount of grease to be dispensed. As a result, in the second mode, the control circuit 80 can stop the motor 20 from running when the set amount of grease has been dispensed.

[0164] (7) The control circuit 80 can calculate the number of reciprocating strokes of the plunger 50 from the actual rotational speed of the motor 20 and the reduction ratio of the reduction mechanism 43. In other words, the control circuit 80 can estimate the amount of grease to be discharged from the actual rotational speed and the reduction ratio.

[0165] (2. Second Embodiment) <2-1. Differences from the First Embodiment> The second embodiment has the same basic configuration as the first embodiment, so the differences will be explained below. Note that the same reference numerals as in the first embodiment indicate the same components, and refer to the preceding description.

[0166] In the second embodiment, the control circuit 80 performs a target rotation speed setting process that is different from the target rotation speed setting process in the first embodiment. Specifically, in the second mode of the second embodiment, the target rotation speed is set based on a second relationship that is different from the second relationship in the second mode of the first embodiment. In the first mode of the second embodiment, the target rotation speed is set based on the same first relationship as in the first mode of the first embodiment. Except for the target rotation speed setting process, the control circuit 80 performs the same processing as in the first embodiment.

[0167] <2-2. Setting the target rotation speed in the second mode> Referring to Figure 16, the setting of the target rotational speed when the operating mode is the second mode will be explained. In the second mode, the user has a desire to fine-tune the operation of the electric lubricator 1. Therefore, in this embodiment, the second relationship has not only a constant speed region but also a variable speed region. Specifically, the second relationship has a second variable speed region Rv2 and a second constant speed region Rc2. The second variable speed region Rv2 corresponds to the range from the first pull amount X1 to the third pull amount X3b. The third pull amount X3b corresponds to the position between the minimum position and the maximum position. The second constant speed region Rc2 corresponds to the range from the third pull amount X3b to the second pull amount X2. The minimum rotational speed ωmin is associated with the first pull amount X1. The maximum rotational speed ωmax is associated with the third pull amount X3b. In the range from the first pull amount X1 to the third pull amount X3b, the rotational speed increases in proportion to the increase in the pull amount.

[0168] The range from the third pull amount X3b to the second pull amount X2 corresponds to the maximum speed ωmax. In the range from the third pull amount X3b to the second pull amount X2, the rotational speed is constant regardless of the pull amount. The third pull amount X3b is smaller than the third pull amount X3a. Therefore, the range in which the pull amount changes in the second speed variation region Rv2 according to the second embodiment is narrower than the range in which the pull amount changes in the first speed variation region Rv1. The second constant speed region Rc2 according to the second embodiment is wider than the first constant speed region Rc1 and narrower than the second constant speed region Rc2 according to the first embodiment. Therefore, in this embodiment, the user can fine-tune the rotational speed of the motor 20 by operating the trigger 9 while basically rotating the motor 20 at a constant speed.

[0169] <2-3. Setting the target rotation speed> Referring to the flowchart in Figure 17, the target rotational speed setting process performed in S60 by the control circuit 80 according to the second embodiment will be described.

[0170] In S800, the control circuit 80 performs the same processing as in S210. Next, in S810, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S810: YES), it proceeds to process S820. If the control circuit 80 determines that the first mode is set as the operating mode (S810: NO), it proceeds to process S860.

[0171] In S820, the control circuit 80 calculates the correction ratio Pb by multiplying the pull ratio Pa by a correction coefficient. The correction coefficient is the rate of increase in rotational speed in the second mode's shifting region, when the rate of increase in rotational speed in the first mode's shifting region is set to 1. Specifically, the correction coefficient = (X3a-X1) / (X3b-X1). After that, the control circuit 80 proceeds to the processing in S830.

[0172] In S830, the control circuit 80 determines whether the correction ratio Pb calculated in S820 is greater than 100%. If the control circuit 80 determines that the correction ratio Pb is greater than 100% (S830: YES), it proceeds to process S840. If the control circuit 80 determines that the correction ratio Pb is 100% or less (S830: NO), it skips process S840 and proceeds to process S850.

[0173] In S840, the control circuit 80 sets the correction ratio Pb to 100% and proceeds to the process in S850. In S850, the control circuit 80 calculates the target rotational speed using the correction ratio Pb instead of the draw ratio Pa, and then terminates the process. Specifically, the control circuit 80 calculates the target rotational speed based on the formula: Target rotational speed = (ωmax - ωmin) × Pb + ωmin.

[0174] In S860, the control circuit 80 performs the same processing as in S220 and terminates this process.

[0175] <2-4. Effects> The second embodiment described in detail above achieves the effects (1), (2), (4) to (7) of the first embodiment mentioned above, and further achieves the following effects.

[0176] (8) In the first mode, the user can finely adjust the rotation speed of the motor 20 by changing the amount of the trigger 9 over a wide range. In the second mode, the user can drive the motor 20 at a constant rotation speed by operating the trigger 9, and can also finely adjust the rotation speed of the motor 20 by changing the amount of the trigger 9 over a narrow range.

[0177] (3. Third Embodiment) <3-1. Differences from the First Embodiment> The third embodiment has the same basic configuration as the first embodiment, so the differences will be explained below. Note that the same reference numerals as in the first embodiment indicate the same components, and refer to the preceding description.

[0178] In the third embodiment, the control circuit 80 performs a target rotation speed setting process that is different from the target rotation speed setting process in the first embodiment. Specifically, in the second mode of the third embodiment, the target rotation speed is set based on a second relationship that is different from the second relationship of the second mode of the first embodiment. In the first mode of the second embodiment, the target rotation speed is set based on the same first relationship as the first mode of the first embodiment. Except for the target rotation speed setting process, the control circuit 80 performs the same processing as in the first embodiment.

[0179] <3-2. Setting the target rotation speed in the second mode> Referring to Figure 18, the setting of the target rotational speed when the operating mode is the second mode will be explained. In this embodiment, the second relationship includes not only a constant speed region but also a variable speed region. Specifically, the second relationship has a second variable speed region Rv2 and a second constant speed region Rc2. The second variable speed region Rv2 corresponds to the range from the first pull amount X1 to the third pull amount X3a. The second constant speed region Rc2 corresponds to the range from the third pull amount X3a to the second pull amount X2. The first pull amount X1 is associated with a specific rotational speed ωminb. The third pull amount X3a is associated with the maximum rotational speed ωmax. The specific rotational speed ωminb is the minimum rotational speed in the second mode and is greater than the minimum rotational speed ωmin in the first mode. In the range from the first pull amount X1 to the third pull amount X3a, the rotational speed increases in proportion to the increase in pull amount.

[0180] The range from the third pull amount X3a to the second pull amount X2 corresponds to the maximum speed ωmax. In the range from the third pull amount X3a to the second pull amount X2, the rotational speed is constant regardless of the pull amount. Therefore, the range in which the rotational speed changes in the second speed variation region Rv2 according to the second embodiment is narrower than the range in which the rotational speed changes in the first speed variation region Rv1. In the second speed variation region Rv2 according to the second embodiment, a small amount of acceleration or deceleration sufficient to detect air entrapment is permitted. The second constant speed region Rc2 according to the second embodiment is equal to the first constant speed region Rc1 and narrower than the second constant speed region Rc2 according to the first embodiment. Therefore, in this embodiment, the user can fine-tune the rotational speed of the motor 20 by operating the trigger 9 while basically rotating the motor 20 at a constant speed.

[0181] <3-3. Setting the target rotation speed> Referring to the flowchart in Figure 19, the target rotational speed setting process performed in S60 by the control circuit 80 according to the third embodiment will be described.

[0182] In S900, the control circuit 80 performs the same processing as in S210. Next, in S910, the control circuit 80 determines whether the second mode is set as the operating mode. If the control circuit 80 determines that the second mode is set as the operating mode (S910: YES), it proceeds to process S920. If the control circuit 80 determines that the first mode is set as the operating mode (S910: NO), it proceeds to process S930.

[0183] In S920, the control circuit 80 calculates the target rotational speed using a specific rotational speed ωminb instead of the minimum rotational speed ωmin, and then terminates this process. Specifically, the control circuit 80 calculates the target rotational speed based on the formula: Target rotational speed = (ωmax - ωminb) × Pa + ωmin. In S930, the control circuit 80 performs the same processing as in S220 and terminates this process.

[0184] <3-4. Effects> The third embodiment described in detail above achieves the effects (1), (2), (4) to (7) of the first embodiment mentioned above, and further achieves the following effects.

[0185] (9) In the first mode, the user can finely adjust the rotation speed of the motor 20 by changing the amount of the trigger 9 over a wide range. In the second mode, the user can drive the motor 20 at a constant rotation speed by operating the trigger 9, and can also accelerate or decelerate the motor 20 within a range that can suppress false detection or failure to detect air entrapment.

[0186] (4. Fourth Embodiment) <4-1. Differences from the First Embodiment> The fourth embodiment has the same basic configuration as the first embodiment, so the differences will be explained below. Note that the same reference numerals as in the first embodiment indicate the same components, and refer to the preceding description.

[0187] In the fourth embodiment, the control circuit 80 differs from the first embodiment in that, in addition to notifying of air lock when air lock is detected, it stops the motor 20 if air lock is detected for a predetermined period of time. Specifically, the control circuit 80 executes a main process different from the main process in the first embodiment, and additionally executes a continuation determination process. In the fourth embodiment, the control circuit 80 executes the target rotation speed setting process according to any of the first to third embodiments.

[0188] <4-2. Processing> <4-2-1. Main Processing> Referring to the flowchart in Figure 20, the main processing performed by the control circuit 80 according to the fourth embodiment will be described.

[0189] In steps S15 to S55, the control circuit 80 executes the processes in S10 to S50. After executing the process in S45 or S55, the control circuit 80 proceeds to the process in S65. In S65, the control circuit 80 sets the air lock status to "not detected" and sets the duration of the air lock to "0". After that, the control circuit 80 proceeds to the process in S145.

[0190] If the control circuit 80 determines in the process of S15 that the trigger switch 8 is ON (S15: YES), it proceeds to the process of S75. In S75, the control circuit 80 determines whether the continuation state of air lock is set to "detected". In the continuation determination process described later, if the continuation state of air lock is detected, the continuation state is set to "detected". If the control circuit 80 determines that the continuation state is set to "detected" (S75: YES), it proceeds to the process in S135. If the control circuit 80 determines that the continuation state is set to "not detected" (S75: NO), it proceeds to the process in S85.

[0191] In steps S85 to S115, the control circuit 80 performs the same processing as in steps S60 to S90. After performing the processing in step S105 or S115, the control circuit 80 proceeds to the processing in step S125. In S125, the control circuit 80 performs a continuation determination process to determine whether the air lock has continued for a predetermined time or longer. Details of the continuation determination process will be described later. After that, the control circuit 80 proceeds to the process in S145.

[0192] In S135, the control circuit 80 stops the motor 20 because the air lock has persisted for a predetermined time or longer. Specifically, the control circuit 80 outputs the first to sixth stop signals to the drive circuit 82 to stop the motor 20. After that, the control circuit 80 proceeds to the process in S145.

[0193] In steps S145 to S165, the control circuit 80 performs the same processing as in steps S100 to S150.

[0194] <4-2-2. Continuation Determination Process> Referring to the flowchart in Figure 21, the continuation determination process executed by the control circuit 80 in S125 will be explained.

[0195] In S205, the control circuit 80 determines whether "detected" is set for the air lock condition. If "detected" is set for the air lock condition (S205: YES), the control circuit 80 proceeds to process S225. If "not detected" is set for the air lock condition (S205: NO), the control circuit 80 proceeds to process S215.

[0196] In S215, the control circuit 80 sets the duration of air entrapment to "0" and terminates this process. In S225, the control circuit 80 accumulates the duration of the air lock. Specifically, the control circuit 80 adds the processing cycle to the current duration. The processing cycle is the time from the execution of the previous continuation determination process to the execution of the current continuation determination process. After that, the control circuit 80 proceeds to the process in S235.

[0197] In S235, the control circuit 80 determines whether the duration is equal to or greater than a predetermined time. If the control circuit 80 determines that the duration is equal to or greater than the predetermined time (S235: YES), it proceeds to process S245. If the control circuit 80 determines that the duration is less than the predetermined time (S235: NO), it terminates this process.

[0198] In S245, the control circuit 80 sets the continuation state to "detected" and terminates this process.

[0199] <4-3. Effects> The fourth embodiment described in detail above achieves the effects (1) to (9) of the first embodiment mentioned above, and further achieves the following effects.

[0200] (10) The control circuit 80 stops the motor 20 if the air-entry condition persists for a predetermined time. This prevents the motor 20 from continuing to operate without grease being dispensed.

[0201] (5. Correspondence between terms) In the first to fourth embodiments, the trigger 9 corresponds to an example of a drive switch in the summary of the embodiments. In the first to fourth embodiments, the second switch 72 and the third switch 73 correspond to an example of a selection switch in the summary of the embodiments.

[0202] (6. Other Embodiments) Although the first to fourth embodiments of this disclosure have been described above, this disclosure is not limited to the first to fourth embodiments and can be implemented in various modified forms.

[0203] (a) In the above embodiment, the pump 60 was a reciprocating pump equipped with a plunger, but it is not limited to this, and any type of pump driven by the motor 20 may be used. The pump 60 may be a reciprocating pump such as a piston pump or a diaphragm pump. Alternatively, the pump 60 may be a rotary pump such as a gear pump, a screw pump or a vane pump. Alternatively, the pump 60 is not limited to positive displacement pumps such as reciprocating pumps or rotary pumps, but may also be a non-positive displacement pump such as a centrifugal pump, a propeller pump or a viscous pump. Regardless of the type of pump the pump 60 is, the control circuit 80 can estimate the amount of grease to be discharged from the actual rotational speed of the motor 20, the reduction ratio and a predetermined amount to be discharged in one cycle.

[0204] (b) In the above embodiment, the lubricant discharged by the electric lubricator 1 was a semi-solid grease, but the lubricant is not limited to grease. The lubricant may be a liquid lubricating oil, or a material other than grease or lubricating oil that has lubricating properties.

[0205] (c) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configurations of the above embodiment may be omitted. Furthermore, at least some of the configurations of the above embodiment may be added to or replaced with the configurations of other above embodiments. [Explanation of Symbols]

[0206] 1...Electric lubricator, 8...Trigger switch, 9...Trigger, 20...Motor, 28...Sensor circuit board, 28A~28C...Third rotation position sensor, 43...Reduction mechanism, 50...Plunger, 63...Chamber, 66...Discharge path, 66A...Discharge port, 67...Air drain valve, 68...Hose, 69...Relief valve, 70...Operation panel, 71...First switch, 72...Second switch, 73...Third switch, 74...First display screen, 75...Set count display screen, 82...Drive circuit.

Claims

1. It is an electric lubricator, A motor configured to generate driving force, A drive circuit configured to drive the motor, A pump having a discharge port configured to discharge a lubricant, and configured to discharge the lubricant from the discharge port at a speed corresponding to the rotational speed of the motor by the driving force generated by the motor, A drive switch configured to be manually operated by the user in order to drive the motor, A selection switch configured to be manually operated by the user to select a first mode or a second mode, wherein the first mode and the second mode are operating modes of the electric lubricator, the first mode associates the amount of operation of the drive switch with the rotational speed in a first relationship, the second mode associates the amount of operation with the rotational speed in a second relationship different from the first relationship, the gear range in the first relationship is wider than the gear range in the second relationship, and the gear range is such that the rotational speed changes according to the amount of operation, A control circuit is configured to control the motor via the drive circuit based on the actual amount of operation of the manually operated drive switch and the first mode or the second mode selected via the selection switch. An electric lubricator equipped with this feature.

2. The control circuit is configured such that, when the first mode is selected via the selection switch, it continues to drive the motor via the drive circuit while the drive switch is being operated. The electric lubricator according to claim 1.

3. The control circuit is configured such that, when the second mode is set via the selection switch, it stops the motor via the drive circuit based on the fact that a set amount of the lubricant has been discharged from the discharge port. The electric lubricator according to claim 1 or 2.

4. The control circuit is configured to estimate the amount of lubricant discharged from the discharge port, or to acquire the measured amount of lubricant, when the second mode is selected via the selection switch. An electric lubricator according to any one of claims 1 to 3.

5. The aforementioned pump, A chamber configured to contain the lubricant and communicate with the discharge port, The system further includes a plunger configured to reciprocate within the chamber by the aforementioned driving force, thereby discharging the lubricant from the discharge port, The control circuit is configured to estimate the discharge amount based on the number of times the plunger reciprocates within the chamber. The electric lubricator according to claim 4.

6. The first relationship has the aforementioned gear shift range, The second relationship described above has a constant speed region and does not have the variable speed region. The constant speed region is one in which the rotational speed is constant regardless of the manipulated amount. An electric lubricator according to any one of claims 1 to 5.

7. The first relationship has a first gear shift region which is the gear shift region, The second relationship described above has a constant speed region and a second variable speed region which is the variable speed region, In the constant speed region, the rotational speed is constant regardless of the manipulated amount. In the second gear shift region, the range in which the operating amount changes is narrower than the range in which the operating amount changes in the first gear shift region. An electric lubricator according to any one of claims 1 to 5.

8. The first relationship has a first gear shift region which is the gear shift region, The second relationship described above has a constant speed region and a second variable speed region which is the variable speed region, In the constant speed region, the rotational speed is constant regardless of the manipulated amount. The range in which the rotational speed changes in the second gear shift region is narrower than the range in which the rotational speed changes in the first gear shift region. An electric lubricator according to any one of claims 1 to 5.

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