JP2019203463A - Grease discharge device - Google Patents

Abstract

To provide a grease discharge device which measures the reciprocation frequency of a plunger without being subject to limitations on arrangement, shapes, and wiring etc. of a detection member and a detected member.SOLUTION: A grease gun 1 includes: a DC motor 5; a power transmission part (a speed reduction mechanism 8) to which rotation is transmitted by driving of the DC motor 5; a plunger 52 which is reciprocated by the power transmission part; grease supply means (a tank 12) which supplies grease to a forward side relative to a return side dead center of the plunger 52; a pump which discharges the grease by reciprocating movement of the plunger 52; a battery (a battery pack) which can supply electric power to the DC motor 5; and rotation detection means (a magnet 57 and a magnetic sensor 59) which can detect rotation of the power transmission part.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a grease discharge device capable of discharging a lubricant (grease).

  As a grease discharge device, for example, Patent Document 1 includes a tank that stores grease, a motor, a plunger that reciprocates by driving the motor, and a pump that operates by reciprocating movement of the plunger. A grease gun is known in which the grease in the tank can be discharged from the discharge port of the pump by reciprocating.

Japanese Utility Model Publication No. 53-5678

When using the above grease gun, there is a case where it is desired to make the discharge amount of grease constant depending on the work location or the like, but it is difficult for the operator to select the discharge amount by adjusting the operation time of the switch. Therefore, it is conceivable that the number of reciprocations of the plunger can be arbitrarily set and the plunger is reciprocated in a limited manner according to the set number of reciprocations.
In this case, in order to confirm that the number of times of reciprocation of the plunger has reached the set number of times, detection means for measuring the number of times of reciprocation of the plunger is necessary. For this measurement, for example, a detected member such as a magnet is attached to the plunger. This can be realized by installing a detection member such as a magnetic sensor at the top dead center of the attachment and reciprocation of the plunger.
However, installing a magnet or the like on the plunger itself may limit the arrangement and shape of the plunger itself. In addition, since a magnetic sensor or the like and wiring therefor are installed in the vicinity of the reciprocating plunger, the arrangement and wiring of the magnetic sensor or the like are easily restricted.

  Therefore, an object of the present invention is to provide a grease discharge device capable of measuring the number of reciprocations of a plunger without being restricted by the arrangement, shape, wiring, and the like of detection members and detected members.

In order to achieve the above object, an invention according to claim 1 is directed to a motor, a power transmission unit to which rotation is transmitted by driving the motor, a plunger that reciprocates by the power transmission unit, and a return side dead end of the plunger. Comprising a grease supply means for supplying grease to the forward movement side from the point, a pump for discharging grease by reciprocating movement of the plunger, and a battery capable of supplying electric power to the motor. Rotation detecting means capable of detecting the rotation of is provided.
According to a second aspect of the present invention, in the configuration of the first aspect, the power transmission unit includes a spindle, and the rotation detecting means detects the rotation of the spindle.
According to a third aspect of the present invention, in the configuration of the first or second aspect, the rotation detection means includes a magnet provided on the rotation side and a magnetic sensor provided on the non-rotation side.

  According to the present invention, the number of reciprocations of the plunger can be measured by detecting the rotation of the power transmission unit. Therefore, there is no need to provide a detection member such as a magnet on the plunger, or a detection member such as a magnetic sensor around the plunger. Therefore, there is no restriction on the arrangement, shape, wiring, etc. of the rotation detection means. The number of round trips can be measured.

It is a perspective view of a grease gun. It is a left view of a grease gun. It is a top view of a grease gun. (A) is a right side view of the grease gun, (B) is a front view. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a BB line partial expanded sectional view of Drawing 5. FIG. 7 is a partial enlarged cross-sectional view taken along the line C-C in FIG. It is a circuit block diagram of an electric control system. It is explanatory drawing of the example of a change using a large diameter tank and a joint, (A) is the state using a large diameter cartridge, (B) shows the state using the cartridge which has a small diameter exit, respectively. It is explanatory drawing which shows operation | movement of a plunger, (A) shows an intermediate point, (B) shows the position which descend | falled a little from the intermediate point, (C) shows a bottom dead center.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a perspective view showing a grease gun as an example of a grease discharge device, FIG. 2 is a left side view, FIG. 3 is a plan view, FIG. 4 (A) is a right side view, and FIG. 5 is a cross-sectional view taken along line AA in FIG.
The grease gun 1 has a main body housing 2 in which left and right half housings 2a, 2b are assembled by screws 31, 31,... (FIG. 4), and a cylindrical motor housing portion 3 is provided below the main body housing 2. However, the grip part 4 is formed in the front-rear direction at the upper part, and the front and rear ends of the grip part 4 are connected to the motor housing part 3 to form a loop. A DC motor 5 is housed in the motor housing portion 3 with the output shaft 6 facing forward, and a gear housing 7 housing a speed reduction mechanism 8 as a power transmission portion is assembled in front of the DC motor 5. ing. A cylindrical front holder 9 that protrudes downward from the main body housing 2 and opens rearward is formed at the front portion of the gear housing 7, and a rear portion that protrudes downward and has a through hole 11 at the rear portion of the motor housing portion 3. A holder 10 is formed, and a tank 12 as a grease supply means is supported in the front-rear direction by the front holder 9 and the rear holder 10.

On the other hand, a trigger switch 13 having a trigger 14 projecting downward is accommodated in the grip portion 4, and a light 15 using LEDs is provided in front of the grip portion 4 and on the front surface of the main body housing 2. A light switch 16 for turning on / off the light 15 is provided on the upper surface of the front part of the unit 4. In front of the trigger 14, the grip portion 4 is provided with a lock-on button 17 that can maintain the pushing state of the trigger 14. The light 15 is used to illuminate a grease supply location, and this illumination improves usability in a dark place.
Further, a battery mounting portion 18 is formed in the main body housing 2 behind the grip portion 4 and accommodates the controller 19 and the terminal block 20 in the front-rear direction and in the vertical direction. A battery pack 21 as a battery can be slidably mounted on the terminal block 20 from above. The controller 19 is provided with a dial 22 for setting the number of reciprocations (pumping times) of the plunger 52, which will be described later, in a state where a part is exposed from the left side surface of the battery mounting portion 18, and the number of times is determined by a rotating operation. It can be set.
Further, the left and right side surfaces of the battery mounting portion 18 and the left and right side surfaces of the motor housing portion 3 and the left and right side surfaces of the motor housing portion 3 are intake ports 23 for sucking external air by rotation of a fan (not shown) provided in the DC motor 5. 23 are formed on the left and right side surfaces between the front and rear intake ports 23, 23 in the motor housing portion 3, and exhaust ports 24, 24,... For discharging the air after cooling of the DC motor 5 are formed. Yes. The controller 19 is also cooled by this air flow.

On the upper surface of the main body housing 2, it is supported between the left and right convex portions 26, 26 at the center in the left-right direction between the light 15 and the light switch 16 and between the grip portion 4 and the battery mounting portion 18. Shoulder belt mounting portions 25, 25 each including a pin 27 in the left-right direction are provided, and the portability of the grease gun 1 is improved by the mounting of the shoulder belt. Further, on the front surface of the main body housing 2, on the upper side of the light 15, a flange portion 28 that protrudes obliquely upward and whose upper surface has an arc shape protrudes. When the carabiner or the like attached to the front shoulder belt attaching portion 25 hangs down, this collar portion 28 is for biasing to the left or right by abutting against the upper surface of the collar portion 28. It is possible to prevent the end of the shoulder belt from covering the light 15 and blocking the light emitted from the light 15. The light 15 can be turned on and off independently by operating the light switch 16.
Furthermore, a hose clamp 29 for inserting and storing an extension hose (not shown) connected to a hose 77 described later is provided on the side surface of the rear holder 10. The hose clamp 29 is a rubber tubular body, and is fixed in a posture facing in the front-rear direction by screwing into a screw hole 30 (FIG. 4) provided on the side surface of the rear holder 10. The screw holes 30 are provided on both side surfaces of the rear holder 10 so that the hose clamp 29 can be attached to either the left or right side.

The speed reduction mechanism 8 is formed by arranging carriers 36, 36,... Supporting the four planetary gears 37, 37,... In three stages in the axial direction in an internal gear 35 held at the rear part of the gear housing 7. . The last stage planetary gears 37, 37... Mesh with a pinion 38 provided on the output shaft 6, and the foremost stage carrier 36 is connected to a spindle 40 supported by front and rear bearings 39, 39 in the gear housing 7. Has been. A crank disk 41 having an eccentric pin 42 protruding forward is fixed to the front end of the spindle 40, and a long hole 44 in the left-right direction is provided in front of the crank disk 41 as shown in FIGS. The slider 43 is provided between the support plates 45 provided on the left and right at the front portion of the gear housing 7 so as to be movable up and down.
Before and after the slider 43, a slider guide 46 fixed to the gear housing 7 on the outer peripheral side of the crank plate 41, and a cover that is screwed between the front ends of the support plates 45 and 45 to cover the crank plate 41 and the slider 43 from the front. 47 is provided. A pair of protrusions 48, 48 (FIG. 6) projecting rearward are formed at the left and right ends of the rear surface of the slider 43, and the protrusions 48, 48 are formed at the left and right ends of the front surface of the slider guide 46. Are formed in a vertical direction with a pair of guide grooves 49 and 49 fitted from the left and right outer sides. In addition, two protrusions 50, 50 that are in contact with the cover 47 are provided on the left and right ends of the front surface of the slider 43.

Therefore, the slider 43 is supported so as to be movable in the vertical direction along the slider guide 46 in a state where the forward and backward movement is restricted between the slider guide 46 and the cover 47. Here, the protrusions 48, 48 of the slider 43 are fitted into the guide grooves 49, 49 provided in the slider guide 46 from the left and right outer sides, so that a guide structure with high rigidity can be obtained while making the dimensions in the left-right direction compact. It has become.
The eccentric pin 42 is loosely inserted into the long hole 44 of the slider 43 via the roller 51, and the upper end of a rod-like plunger 52 extending in the vertical direction is connected to the center of the lower end of the slider 43.
Thus, when the crank disk 41 is rotated together with the spindle 40 between the support plates 45 and 45, the eccentric movement of the eccentric pin 42 causes the slider 43 to reciprocate up and down by the amount of movement of the eccentric pin 42 in the vertical direction. A crank mechanism for moving 52 up and down is formed.

On the other hand, in the gear housing 7, between the front and rear bearings 39, 39 that support the spindle 40, as shown in FIG. A magnet 57 is embedded in the provided flange portion 56 at a position eccentric from the axis of the spindle 40.
An opening 58 is formed on the left side of the gear housing 7 behind the flange portion 56 so that the bearings 39 communicate with the inside of the main body housing 2. The hall element 60 is formed on the front surface of the opening 58. A magnetic sensor 59 made of a substrate 61 on which is mounted is inserted and fixed horizontally. This magnetic sensor 59 can detect the magnetic field of the magnet 57 when approaching by the eccentric motion accompanying the rotation of the spindle 40.

FIG. 8 is a circuit block diagram of an electric control system. The controller 19 includes a control power supply circuit 65 that creates an operating power supply from a power supply obtained from the battery of the battery pack 21, a voltage detection circuit 66 that detects a power supply voltage, A main control circuit 67 is provided.
The trigger switch 13 includes a motor current cut-off contact 13a for cutting off the current from the battery to the DC motor 5, a main switch 13b for turning on / off the drive of the DC motor 5, and a DC according to the pulling margin of the trigger 14. A trigger shift input unit 13 c for adjusting the rotation speed of the motor 5 is provided, and an ON signal of the main switch 13 b and a variable signal of the trigger shift input unit 13 c are input to the main control circuit 67. Further, an ON signal of the light switch 16, a variable signal of the dial 22, and a detection signal of the magnetic sensor 59 are also input to the main control circuit 67. Reference numeral 68 denotes an FET that is turned ON / OFF by the main control circuit 67 in order to cause a drive current to flow to the DC motor 5, and 69 denotes a current detection amplifier for detecting the current flowing to the DC motor 5.
Further, the main control circuit 67 has a function of shifting to a power saving mode in which power consumption is suppressed by elapse of a certain time or long pressing of the light switch 16. The power saving mode is a function of the light switch 16 and the trigger switch 13. When any ON with the main switch 13b is detected, it returns.

A pump 70 is provided in the front holder 9 of the gear housing 7 to discharge grease supplied from the tank 12 by the vertical movement of the plunger 52. The pump 70 protrudes upward from the lower inner surface of the front holder 9 coaxially with the upper cylinder portion 71 and protrudes upward from the lower inner surface of the front holder 9. The lower cylinder part 72 which has the clearance gap 73 connected with the inside of the holder 9 is comprised. The plunger 52 moves up and down through the upper cylinder portion 71 and the lower cylinder portion 72, but at the top dead center, the lower end is substantially immersed in the upper cylinder portion 71 above the gap 73 as shown in FIG. At the bottom dead center, as shown in FIG. 10C, the lower end reaches the substantially middle part in the lower cylinder part 72. In the lower cylinder portion 72, a vertical discharge path 74 that is communicated with the gap 73 and through which the plunger 52 is inserted is formed.
In the vertical discharge path 74, the part below the lower end of the plunger 52 at the bottom dead center is a large diameter path 75 having a larger diameter than the insertion part of the plunger 52, and the lower cylinder portion 72 communicates with the large diameter path 75. A lateral discharge path 76 (FIG. 5) is formed in a forward direction, and the vertical discharge path 74 including the large diameter path 75 and the horizontal discharge path 76 form a grease discharge path. A hose 77 is forwardly connected to the front surface of the front holder 9 serving as an outlet of the lateral discharge path 76. An air valve 78 is provided on the upper side of the hose 77 and on the front surface of the front holder 9 to release internal air to the outside and eliminate defective discharge due to air biting.

The large diameter path 75 of the vertical discharge path 74 is provided with a check valve 80 for preventing a reverse flow of grease from the large diameter path 75. The check valve 80 includes a flat washer 81 provided on the inner surface of the upper end of the large-diameter passage 75, a steel ball 82 capable of opening and closing the opening of the flat washer 81, and a steel ball 82 below the opening of the flat washer 81. And a holding bolt 84 that includes a bottomed hole 85 that holds the coil spring 83 and closes the lower portion of the large-diameter path 75. The upper end portion of the holding bolt 84 is formed to have a smaller diameter than the large diameter path 75 above the opening portion of the horizontal discharge path 76 so as not to prevent communication between the large diameter path 75 and the horizontal discharge path 76.
Here, since the pump 70 is made of aluminum and the steel ball 82 is made of steel, if the steel ball 82 is directly seated on the lower cylindrical portion 72, the lower cylindrical portion 72 may be damaged or dented. Damage is reduced using a flat washer 81 made of steel. By using the flat washer 81 as another member in this way, there is an advantage that even if the flat washer 81 is scratched or dented, it can be easily replaced.

Further, below the bottomed hole 85 in the holding bolt 84, a small hole 87 penetratingly formed at the center of the bottom of the bottomed hole 85 is communicated with the bottomed hole 85 via the small hole 87. An escape passage 86 is formed which includes an axial vertical hole 88 formed to the lower end of the front hole 9 and a horizontal hole 89 (FIG. 5) that is orthogonal to the vertical hole 88 and communicates with the outside below the lower surface of the front holder 9. Thus, a relief valve 90 is provided in the escape passage 86. This relief valve 90 has a large-diameter lower end 91a screwed into the lower end of the vertical hole 88 from below, closes the vertical hole 88 below the horizontal hole 89, and extends upward at the axial center in the vertical hole 88. 91, a coil spring 92 mounted on the valve pin 91, and a steel ball 93 provided on the upper side of the coil spring 92.
The relief valve 90 is normally in a closed state in which the steel ball 93 closes the small hole 87 from below by the bias of the coil spring 92. When the pressure in the lateral discharge path 76 increases and exceeds the biasing force of the coil spring 92, the steel ball 93 moves away from the small hole 87 against the biasing of the coil spring 92, and the small hole 87 is passed through the bottomed hole 85. It is made to communicate with the escape path 86 via.
Here, since the relief valve 90 is provided in the holding bolt 84 constituting the check valve 80 and is disposed directly below the check valve 80, the check valve 80 and the relief valve 90 can be formed in a compact space-saving manner. .

A switching valve 95 is provided on the left side surface of the front holder 9 orthogonal to the vertical discharge path 74 in which the check valve 80 and the relief valve 90 are provided. The switching valve 95 is screwed from the left side surface of the front holder 9 at the position of the lower cylinder portion 72 and protrudes into the front holder 9, and the tip is slightly smaller in diameter than the relief recess 96 provided on the left side surface of the lower cylinder portion 72. A main body 97 that is a cylindrical body, a large-diameter left end portion 98 a is screwed into the shaft center of the main body 97 from the outside to close the main body 97, And a steel ball 100 provided on the right side of the coil spring 99.
At the front end of the main body 97, an internal flow path 101 that accommodates the steel ball 100 so as to be movable in the axial direction of the main body 97, a small diameter flow path 102 that communicates coaxially with the internal flow path 101 and opens to the front end axis, A lateral flow path 103 that communicates with the internal flow path 101 in an orthogonal shape and opens on the side surface of the main body 97 is provided. The steel ball 100 is normally biased to a valve closing position where the steel ball 100 is seated on the opening of the small-diameter channel 102 by the coil spring 99 and closes the small-diameter channel 102.
On the other hand, the lower cylinder portion 72 is formed with a communication passage 104 in the left-right direction that allows the vertical discharge passage 74 to escape and communicate with the recess 96 on the upstream side of the steel ball 82 of the check valve 80. 102 to face. The left end of the main body 97 is exposed to the outside of the front holder 9, and a large-diameter operation unit 105 is integrally provided.

The switching valve 95 is screw-moved with respect to the front holder 9 by the rotation operation of the main body 97 by the operation unit 105, the tip of the main body 97 is released and comes into contact with the bottom surface of the concave portion 96, and the communication path 104 becomes the small diameter flow path 102. The automatic switching position that communicates only with the main body 97, the tip of the main body 97 escapes away from the bottom surface of the concave portion 96, the communication passage 104 escapes, opens into the concave portion 96, and communicates with the front holder 9 through the gap with the main body 97 An open position can be selected.
When the automatic switching position is selected, if the pressure in the small diameter flow path 102 communicating with the vertical discharge path 74 via the communication path 104 is lower than the urging force of the coil spring 99, the small diameter flow path 102 is Blocked. When the pressure in the small-diameter channel 102 exceeds the urging force of the coil spring 99, the steel ball 100 is separated from the opening of the small-diameter channel 102 against the urging of the coil spring 99, and the small-diameter channel 102 is opened. Therefore, the grease flowing in from the communication path 104 through the small diameter flow path 102 returns to the front holder 9 from the horizontal flow path 103 through the internal flow path 101 of the main body 97, and releases the pressure in the vertical discharge path 74. Become.

On the other hand, when the manual release position is selected, since the main body 97 is separated from the bottom surface of the escape recess 96, the grease in the vertical discharge path 74 is always released from the communication path 104 via the recess 96 in the front holder 9. Will be able to escape. This escape amount can be adjusted by setting a gap between the main body 97 and the bottom surface of the escape recess 96.
In both the automatic switching position and the manual opening position, according to the switching valve 95, the discharge amount of grease can be changed while the number of reciprocations per unit time of the plunger 52 is constant (the automatic switching position automatically Therefore, in the manual release position, manual adjustment).
The valve pin 98, coil spring 99, and steel ball 100 used in the switching valve 95 are the same components as the valve pin 91, coil spring 92, and steel ball 93 used in the relief valve 90. This is because the pressure adjustment at the relief valve 90 is performed with the diameter of the small hole 87 and the pressure adjustment with the switching valve 95 is performed with the diameter of the small diameter flow path 102. Common parts can be used, leading to cost reduction.

  The tank 12 has a bottomed cylindrical shape with an open front surface, penetrates from the rear through the through hole 11 of the rear holder of the main body housing 2, and is screwed at the front end to the front holder 9, thereby lowering the motor housing portion 3. And is connected to the main body housing 2 in a forward-facing posture. A rod 110 having a piston 111 at the front end is accommodated in the tank 12 so as to be movable in the front-rear direction, and a handle 113 is provided at the rear end of the rod 110 protruding from a through hole 112 provided at the rear end of the tank 12. Is provided. A coil spring 114 is provided behind the piston 111 in the tank 12 to urge the piston 111 forward. A constricted portion 115 is provided on the outer periphery of the rod 110 at a predetermined interval. If the constricted portion 115 is engaged with the through hole 112 of the tank 12 by retreating the rod 110, the coil spring 114 is resisted. Thus, the piston 111 can be positioned at the rear position in the tank 12.

Therefore, if the cylindrical cartridge 116 filled with grease is accommodated in the tank 12 with the piston 111 retracted and the front end is opened, the piston 111 is pushed by the bias of the coil spring 114. The grease is pushed out from the cartridge 116 and supplied to the pump 70.
Some cartridges have a large outer diameter and others have a small-diameter outlet provided at the front end closed by a screw cap. In this case, as shown in FIG. The tank 12A may be connected. The joint 117 has a two-stage cylindrical shape in which a threaded portion 118 to the front holder 9 is formed on the outer periphery of the front side, and a fitting portion 119 of a large-diameter tank 12A is formed on the outer periphery of the rear end. The small-diameter cylinder 120 whose inner diameter is a female screw is formed forwardly.

By using this joint 117, even a cartridge 116A having a large outer diameter can be accommodated without hindrance by connecting a large-diameter tank 12A as shown in FIG. 9A. In this case, the grease pushed out to the piston 111 is supplied to the pump 70 from the small diameter cylinder 120 through the joint 117.
In the case of the cartridge 116B having the small diameter outlet 121, the outlet 121 can be screwed into the small diameter cylinder 120 of the joint 117 as shown in FIG. In this case, the grease pushed out to the piston 111 is supplied from the outlet 121 through the joint 117 to the pump 70. When the size of the outlet 121 of the cartridge 116B is different, the joint 117 having a different size of the small diameter cylinder 120 may be used. By adopting the joint 117 and the tank 12A in this way, it is possible to deal with the two types of cartridges 116A and 116B with most parts in common.

In the grease gun 1 configured as described above, when the tank 12 containing the cartridge 116 is connected to the main body housing 2, the grease pushed out by the piston 111 is filled in the front holder 9.
When the trigger 14 is pushed in in this state, the main control circuit 67 of the controller 19 that detects each signal of the trigger switch 13 turns on the FET 68 to supply a drive current to the DC motor 5 and rotate the output shaft 6. Then, the rotation of the output shaft 6 is decelerated by the reduction mechanism 8 and transmitted to the spindle 40, and the crank disk 41 is rotated at a reduced speed together with the spindle 40. Thereby, the eccentric pin 42 moves eccentrically, and the slider 43 moves up and down, and the plunger 52 is reciprocated up and down together with the slider 43. Therefore, in the pump 70, as shown in FIG. 7, when the plunger 52 reaches the top dead center, the grease is discharged from the gap 73 between the upper cylinder portion 71 and the lower cylinder portion 72 in the vertical discharge path 74 of the lower cylinder portion 72. Flow into. Thereafter, when the plunger 52 moves to the bottom dead center shown in FIG. 10C, the grease pushed downward in the vertical discharge path 74 pushes down the steel ball 82 of the check valve 80 and discharges from the large diameter path 75 in the horizontal direction. It flows into the passage 76 and is discharged through the hose 77 as it is. This discharge operation is repeated as the plunger 52 reciprocates.

Here, when the plunger 52 is lowered, as shown in FIG. 10 (A), the eccentric pin 42 has moved from the top dead center shown in FIG. 7 to the right side of the center of rotation of the crank plate 41 (90 ° from the top dead center). At the intermediate point reaching (phase), the position of the eccentric pin 42 is farthest from the rotation center of the crank disk 41, so that the load applied to the DC motor 5 is maximized. However, since the lower end of the plunger 52 is located above the communication path 104 with the switching valve 95, the grease is not discharged.
Then, the plunger 52 further descends from here, and as shown in FIG. 10B, in the phase in which the eccentric pin 42 moves slightly below the phase at the middle point, the lower end of the plunger 52 is connected to the communication path 104. Is exceeded, the grease in the vertical discharge path 74 is pressed to open the check valve 80, and the grease is pushed out to the lateral discharge path 76 until the bottom dead center is reached. That is, since the discharge is performed after the phase at which the load on the DC motor 5 reaches the maximum, the load on the DC motor 5 can be reduced as compared with the case where the discharge is started at the intermediate point.

  On the other hand, when it is desired to discharge a certain amount of grease, when the dial 22 is operated to set the number of reciprocations (pumping times) of the plunger 52 and the trigger 14 is pushed in, the main control circuit of the controller 19 that obtains the variable signal of the dial 22 67 drives the DC motor 5 to rotate the output shaft 6, and the magnetic sensor 59 detects the magnetic field of the magnet 57 that rotates around the shaft together with the spindle 40. When the detection signal reaches the number of reciprocations set by the dial 22, the FET 68 is turned off to stop the driving of the DC motor 5. Therefore, the amount of grease corresponding to the set number of reciprocations of the plunger 52 is discharged from the hose 77.

In the switching valve 95, when the operation unit 105 is switched to the automatic switching position, the load pressure during the discharge operation is relatively small, and the pressure in the small diameter channel 102 of the main body 97 is less than the biasing force by the coil spring 99. In the meantime, the small-diameter channel 102 is closed by the steel ball 100. Therefore, the grease discharged from the pump 70 has a high discharge amount (low pressure).
When the load pressure increases and the pressure in the small diameter channel 102 exceeds the urging force of the coil spring 99, the steel ball 100 is separated from the opening of the small diameter channel 102 against the urging force of the coil spring 99. Therefore, the grease flowing in from the small diameter flow path 102 passes through the internal flow path 101 of the main body 97 and returns from the horizontal flow path 103 into the front holder 9 to release the pressure in the vertical discharge path 74. Since the stroke of the plunger 52 is substantially halved by the operation of the switching valve 95, the grease discharged from the pump 70 has a low discharge amount (high pressure).

On the other hand, when the switching valve 95 is switched to the manual release position, the communication path 104 is always in communication with the inside of the front holder 9 via the recess 96. Therefore, since there is grease that escapes from the communication path 104 and returns to the front holder 9 through the recess 96, the grease discharged from the pump 70 has a low discharge amount. Since this escape amount can be changed by setting the gap between the main body 97 and the bottom surface of the escape recess 96, the degree of freedom of setting is increased.
When the pressure in the lateral discharge passage 76 increases excessively, the steel ball 93 moves backward against the bias of the coil spring 92 in the relief valve 90 and moves forward in the large-diameter passage 75 through the escape passage 86. It communicates with the outside of the holder 9. Therefore, the grease in the lateral discharge path 76 is discharged from the front holder 9 through the escape path 86 from the large diameter path 75, and the pressure in the lateral discharge path 76 is released.

  Thus, according to the grease gun 1 of the said form, DC motor 5, the power transmission part (deceleration mechanism 8) to which rotation is transmitted by the drive of DC motor 5, and the plunger 52 reciprocated by a power transmission part, The grease supply means (tank 12) for supplying grease to the forward movement side of the return side dead center of the plunger 52, the pump 70 for discharging grease by the reciprocation of the plunger 52, and the DC motor 5 are supplied with electric power. And a rotation detecting means (a magnet 57 and a magnetic sensor 59) capable of detecting the rotation of the power transmission unit, thereby detecting the rotation of the power transmission unit. Thus, the number of reciprocations of the plunger 52 can be measured. Therefore, it is not necessary to provide a detection member such as a magnet on the plunger 52 or a detection member such as a magnetic sensor around the plunger 52, so that the plunger is not restricted by the arrangement, shape, wiring, etc. of the rotation detection means. 52 round trip times can be measured.

In particular, here, since the rotation detecting means detects the rotation of the spindle 40 synchronized with the reciprocation of the plunger 52, the number of reciprocations of the plunger 52 can be directly measured by detecting the number of rotations of the spindle 40.
Further, since the rotation detecting means includes a magnet 57 provided on the rotation-side spindle 40 and a magnetic sensor 59 provided on the non-rotation-side gear housing 7, the rotation speed of the spindle 40 is determined. It can be easily measured without contact.

In the above embodiment, the magnet is provided by mounting the holding sleeve on the spindle. However, the shape of the holding sleeve or the like can be changed, and the magnet may be provided directly on the spindle without such a holding member. The mounting structure of the magnetic sensor can also be changed as appropriate, such as the position and orientation.
Further, the object for providing the rotation detecting means may be a crank disk, and is not limited to the spindle, but can be appropriately selected as long as it is a rotating member corresponding to the reciprocation of the plunger, such as a carrier, a gear, an output shaft (pinion) of a DC motor. However, in the case of a rotating member that is not synchronized with the reciprocation of the plunger, it is necessary to convert the number of rotations measured by the controller into the number of reciprocations of the plunger.
Furthermore, the means for setting the number of reciprocations of the plunger is not limited to the dial, and other means such as a lever operation or a push button operation number can be employed.
The rotation detection means is not limited to a magnet and a magnetic sensor. For example, a measurement target provided on the rotation member using a photoelectric sensor or the like is measured in a non-contact manner, or a measurement target provided on the rotation member using a microswitch or the like. Other means such as counting the number of contact of the part can also be adopted.

  In addition, the configuration of the grease gun itself is not limited to the above form, and a brushless motor is used as the motor, or the motor housing part and the grip part are formed in the vertical direction by supporting the tank in the vertical direction instead of the front-rear direction. It can be appropriately changed.

  1 .... Grease gun, 2 .... Main body housing, 3 .... Motor housing part, 4 .... Grip part, 5 .... DC motor, 6 .... Output shaft, 7 .... Gear housing, 8 .... Reduction mechanism, 9 ..Front holder, 10 ..Rear holder, 12 ..Tank, 19 ..Controller, 21 ..Battery pack, 22 ..Dial, 40 ..Spindle, 41 ..Crankboard, 42 ..Eccentric pin, 43 ..Slider, 52 .. Plunger, 55 .. Holding sleeve, 56 .. Flange, 57 .. Magnet, 59 .. Magnetic sensor, 67 .. Main control circuit, 68 .. FET, 70. .. Upper cylinder part, 72 .. Lower cylinder part, 73 ..Gap, 74 ..Vertical discharge path, 75 ..Large diameter path, 76 ..Horizontal discharge path, 77 ..Hose, 80. 81. Flat washer, 90 Relief valve, 95 ... switching valve.

Claims (3)

A motor,
A power transmission unit that transmits rotation by driving the motor;
A plunger that reciprocates by the power transmission unit;
Grease supplying means for supplying grease to the forward movement side from the backward movement dead center of the plunger;
A pump for discharging grease by reciprocating movement of the plunger;
A battery capable of supplying electric power to the motor,
A grease discharge device comprising rotation detection means capable of detecting rotation of the motor or the power transmission unit.   The grease discharging apparatus according to claim 1, wherein the power transmission unit includes a spindle, and the rotation detection unit detects rotation of the spindle.   The grease discharge device according to claim 1, wherein the rotation detection unit includes a magnet provided on a rotation side and a magnetic sensor provided on a non-rotation side.

Images