CN214008811U - Grease discharging device - Google Patents

Grease discharging device Download PDF

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Publication number
CN214008811U
CN214008811U CN202022090934.2U CN202022090934U CN214008811U CN 214008811 U CN214008811 U CN 214008811U CN 202022090934 U CN202022090934 U CN 202022090934U CN 214008811 U CN214008811 U CN 214008811U
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China
Prior art keywords
valve
grease
passage
pressure
pump
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CN202022090934.2U
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Chinese (zh)
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川井智史
田中孝治
萩原秀郁
福冈彻
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Makita Corp
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Makita Corp
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16NLUBRICATING
    • F16N3/00Devices for supplying lubricant by manual action
    • F16N3/10Devices for supplying lubricant by manual action delivering grease
    • F16N3/12Grease guns

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Safety Valves (AREA)
  • Reciprocating Pumps (AREA)
  • Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)

Abstract

The utility model provides a lubricating grease eduction gear. A longitudinal discharge passage and a lateral discharge passage (66) for grease discharged from a pump are formed in a front holder (12) of a grease gun (1), and a relief valve (80) for releasing the pressure in the lateral discharge passage (66) is provided in the lateral discharge passage (66). The relief valve (80) has: an overflow channel (87) that communicates with the lateral discharge passage (66); a valve pin (82) that is slidable between a valve-closed position and a valve-open position of a valve seat (94) provided in the relief flow path (87); and a coil spring (84) for biasing the valve pin (82) to the valve-closing position. A groove for releasing the inward pressure generated on the valve seat (94) side of the valve pin (82) to the opposite side of the valve pin (82) to the valve seat (94) is formed on the outer periphery of the valve pin (82). This can suppress variation in the operating pressure of the relief valve.

Description

Grease discharging device
Technical Field
The utility model relates to a lubricating grease eduction gear that can discharge emollient (lubricating grease).
Background
As a grease discharge device, for example, patent document 1 discloses a grease gun having a container for storing grease, a motor, a plunger driven by the motor to reciprocate, and a pump operated by the reciprocation of the plunger. In this grease gun, the grease in the tank can be pumped and discharged from the discharge port by reciprocating the plunger by driving the motor.
The grease gun is provided with a relief valve that discharges grease in the middle of the flow to release pressure when the pressure in a discharge passage from the pump to the discharge port increases. The relief valve is configured to abut a ball against a valve seat provided in a relief flow path communicating with the discharge path and to apply a force to the ball by a coil spring.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2019-203463
SUMMERY OF THE UTILITY MODEL
[ problem to be solved by the present invention ]
In the relief valve, since the ball is directly pressed by the coil spring, when the coil spring is inclined in the relief flow path, the biasing force of the coil spring is unstable, and the relief valve may not be operated at an appropriate operating pressure.
Therefore, a structure is considered in which the ball is held by the valve pin and the valve pin is biased to the valve-closing position by the coil spring. In this case, the biasing force of the coil spring can be stably transmitted to the ball by sliding the valve pin in the axial direction in the relief flow path.
However, in the case of this structure, grease tends to remain in the space between the valve pin and the valve seat, and internal pressure is generated in the space, and variation in operating pressure occurs due to the internal pressure.
Therefore, an object of the present invention is to provide a grease discharging device capable of suppressing variation in the operating pressure of a relief valve.
[ solution for solving problems ]
In order to achieve the above object, the present invention is characterized by comprising: a motor; a pump that is driven by the motor to operate; a motor housing that houses the motor; and a pump housing having a pump, the pump housing having a discharge passage for grease discharged from the pump, the discharge passage being provided with a relief valve for releasing pressure in the discharge passage, the relief valve having: an overflow passage communicating with the discharge passage; a valve body that is slidable between a valve-closed position and a valve-open position of a valve seat provided in the relief flow path; and an urging member that urges the valve body to a valve-closed position, wherein the valve body is provided with a release passage for releasing an internal pressure generated on a valve seat side of the valve body to a side opposite to the valve seat side of the valve body.
Another aspect of the present invention is characterized in that, in the above structure, the relief passage is a groove formed on the outer periphery of the valve element.
Another aspect of the present invention is characterized in that, in the above structure, the groove is formed in plural.
In another aspect of the present invention, in the above structure, the valve body has a ball located at the valve seat in the valve-closed position, and the valve seat has a spherical shape along an outer surface shape of the ball.
Another aspect of the present invention is characterized in that, in the above structure, the outer side of the valve seat in the overflow flow path is a tapered surface having the valve seat as a bottom.
Another aspect of the present invention is characterized in that, in the above structure, the urging member is a coil spring.
The utility model discloses a characterized in that of other modes, in above-mentioned structure, the pump includes: a plunger that reciprocates by driving of a motor; and a pressure-feeding cylinder section into which the plunger is inserted and removed, wherein an outlet cylinder section formed to protrude from the pump housing is connected to the pressure-feeding cylinder section, and a discharge passage is formed inside the pressure-feeding cylinder section and the outlet cylinder section.
In another aspect of the present invention, in the above-described structure, a connection path communicating with the outlet cylinder portion is formed in the pump housing, and the relief valve is connected to the connection path in a split-type unitized manner, so that the relief flow path communicates with the connection path.
In another aspect of the present invention, in the above configuration, the cross-sectional shape of the connection passage is an oblong or oval shape extending in the circumferential direction of the outlet tube portion.
In another aspect of the present invention, in the above configuration, a cross-sectional shape of the discharge passage in the outlet cylinder portion connected to the pressure-feed cylinder portion is an oblong or elliptical shape extending in a circumferential direction of the pressure-feed cylinder portion.
In another aspect of the present invention, in the above configuration, the plunger and the pressure-feeding cylinder portion are disposed in the vertical direction, and the outlet cylinder portion is formed to protrude forward.
In another aspect of the present invention, in the above-described structure, the motor housing is disposed above the pump housing, and the annular handle portion is provided above the motor housing in the front-rear direction.
Another aspect of the present invention is characterized in that, in the above structure, an installation portion of the battery pack is provided at a rear end of the handle portion.
Another aspect of the present invention is characterized in that, in the above structure, a container for supplying grease to the pump is connected to the pump housing in the front-rear direction.
[ effects of utility model ]
According to the utility model discloses, through form the release route on the case of overflow valve, the case can not receive the influence of the interior pressure that produces at the disk seat side and work. Therefore, variation in the operating pressure of the relief valve can be suppressed.
Drawings
Fig. 1 is a perspective view of a grease gun.
FIG. 2 is a central longitudinal sectional view of the grease gun.
Fig. 3 is a sectional view a-a of fig. 2.
Fig. 4 is a sectional view B-B of fig. 2.
Fig. 5 is an enlarged sectional view of C-C of fig. 2.
Fig. 6 is an explanatory view of the relief valve, in which (a) is a side face where a valve cover is omitted, (B) is a D-D sectional view, and (C) is an E-E sectional view.
Fig. 7 is an enlarged view of a portion F of fig. 6.
Fig. 8 is an explanatory view of the front holder, in which (a) shows a side surface and (B) shows a front surface.
Description of the reference numerals
1: a grease gun; 2: a main body housing; 4: a motor housing portion; 5: a handle portion; 8: a DC motor; 9: an output shaft; 10: a gear housing; 11: a speed reduction mechanism; 12: a front retainer; 13: a container; 30: a controller; 32: a battery pack; 40: an operation knob; 50: a main shaft; 51: a crank disk; 53: a slider; 59: a plunger; 60: a pump; 61: an upper cylinder part; 62: a lower cylinder part; 63: a gap; 64: a longitudinal discharge passage; 66: a lateral discharge path; 67: a front barrel portion; 68: a hose; 70: a check valve; 75: a connection path; 80: an overflow valve; 81: a valve bolt; 82: a valve pin; 83: a ball bearing; 84: a coil spring; 87: an overflow flow path; 93: a conical surface; 94: a valve seat; 98: a groove; 100: a switching valve; s: a space.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
Fig. 1 is a perspective view showing a rechargeable grease gun as an example of a grease discharging device. FIG. 2 is a central longitudinal sectional view of the grease gun.
The grease gun 1 has a main body casing 2. The main body case 2 is assembled by right and left half cases 2a and 2b with screws 3 and 3 … … inserted from the right side. A cylindrical motor housing portion 4 is formed in the front-rear direction at the lower portion of the main body housing 2. A grip portion 5 is formed in the front-rear direction on the upper portion of the main body casing 2. A wide width portion 6 having a larger lateral width than the grip portion 5 is formed in front of the motor housing portion 4. The front end of the grip portion 5 is bent downward and connected to the wide portion 6. The rear ends of the motor case 4 and the handle 5 are connected to the battery mounting portion 7 in a ring shape. The DC motor 8 is housed in the motor case 4 in a posture in which the output shaft 9 is directed forward. A gear housing 10 is assembled in front of the DC motor 8. The reduction mechanism 11 is housed in the gear housing 10.
The front portion of the gear housing 10 protrudes downward from the inside of the wide portion 6. A cylindrical front holder 12 that opens rearward is formed at the lower portion of the gear housing 10. The front holder 12 is connected to the container 13 from the rear. A rear holder 14 projecting downward is provided below the motor case 4 and behind the front holder 12. The rear holder 14 supports the container 13 in the front-rear direction. The rear holder 14 includes a front leg portion 15, a rear leg portion 16, and a connecting portion 17. The front leg 15 is annular and is adjacent to the front holder 12 and through which the front portion of the container 13 passes. The rear leg portion 16 is annular and is spaced rearward from the front leg portion 15, and an intermediate portion of the container 13 is inserted therethrough. The connecting portion 17 extends in the front-rear direction, and connects the front leg portion 15 and the rear leg portion 16 at the lower side of the container 13. A projection 18 projecting to the left outside is integrally formed on the left side surface at the lower end of the front leg portion 15.
The trigger switch 20 is housed in the handle portion 5. The trigger switch 20 has a trigger 21 protruding downward. A lamp 22 using an LED is provided on the front surface of the grip portion 5. A lamp switch 23 for turning on/off the lamp 22 is provided on the front upper surface of the grip portion 5. A lock button 24 capable of maintaining the push-in state of the trigger 21 is provided on the grip portion 5 in front of the trigger 21. An unlock button 25 for restricting the push-in of the trigger 21 is provided below the lock button 24 and in front of the trigger 21.
The controller 30 and the connection terminal 31 are housed in the battery mounting portion 7 in a vertically forward and backward arrangement. The battery pack 32 as a power source is slidably attached to the terminal 31 from above.
Air inlets 33 … … are formed in the left and right side surfaces of the battery mounting portion 7, the rear portion of the motor case portion 4, and the left and right side surfaces of the intermediate portion. The air inlet 33 sucks in external air by rotation of an unillustrated fan provided in the DC motor 8. Air outlet ports 34, 34 … … are formed in the left and right side surfaces of the motor case 4 between the front and rear air inlet ports 33, and air having cooled the DC motor 8 is discharged through the air outlet ports 34, 34 … ….
Pins 35, 35 in the left-right direction supported between the left and right convex portions are provided on the upper surface of the main body housing 2. The pins 35, 35 are provided at the center in the left-right direction between the lamp 22 and the lamp switch 23 and between the handle portion 5 and the battery mounting portion 7. The grease gun 1 can be suspended by attaching both ends of the shoulder strap to the pins 35, 35.
A brim 36 is formed on the front surface of the main body case 2 and above the lamp 22. The brim 36 projects obliquely upward, and the upper surface is formed in an arc shape. The eaves 36 is provided to be offset to one of the right and left sides by abutting on the upper surface of the eaves 36 when a hook and loop attached to the front pin 35 hangs down. The eaves 36 prevent the ends of the shackle or shoulder straps from blocking the light 22 and blocking the light emitted from the light 22. Further, the lamp 22 can be turned on and off individually by the operation of the lamp switch 23.
A hose clamp 37 is provided at the center in the front-rear direction of the upper portion of the left side surface of the rear holder 14. The hose clamp 37 is provided for inserting and storing an extension hose, not shown, connected to a hose 68 described later. The hose clamp 37 is a rubber cylindrical body, and is fixed by screws in a posture facing the front-rear direction on the side surface of the rear holder 14. The hose clamp 37 can be mounted on either of the two sides of the rear holder 14.
An operation knob 40 is provided on the left side surface of the front holder 12. The operation knob 40 is provided in a switching valve 100 described later and switches and operates the discharge amount of grease.
In the case where the hose clamp 37 is mounted on the left side surface, when the grease gun 1 is tilted leftward and placed horizontally on a flat surface, the convex portion 18 and the hose clamp 37 provided on the rear holder 14 abut against the flat surface. Therefore, the grease gun 1 is supported obliquely, and the operation knob 40 does not abut on the flat surface between the convex portion 18 and the hose clamp 37.
As shown in fig. 4, the reduction mechanism 11 has an internal gear 45, and the internal gear 45 is held at the rear of the gear housing 10. Within the ring gear 45, three-stage planetary carriers 46, 46 … … are arranged in an axial direction. Each carrier 46 supports four planet gears 47, 47 … …, respectively. The rearmost planetary gears 47, 47 … … mesh with a pinion gear 48 provided on the output shaft 9. The forward-most carrier 46 is connected to a main shaft 50, and the main shaft 50 is supported by front and rear bearings 49, 49 in the gear housing 10. A crank disc 51 for projecting an eccentric pin 52 forward is fixed to the front end of the main shaft 50. As shown in fig. 3, a slider 53 is provided in front of the crank disc 51, and the slider 53 has a long hole 54 in the left-right direction. The slider 53 is provided at the front portion of the gear housing 10 and is vertically movable between support plates 55, 55 provided on both the left and right sides.
A slider guide 56 is provided on the rear side of the slider 53. The slider guide 56 is fixed to the gear housing 10 on the outer peripheral side of the crank disk 51. The left and right side edges of the slider 53 folded back abut the left and right sides of the slider guide 56. The eccentric pin 52 penetrates the long hole 54 via the roller 57. A circlip 58 is fitted to the tip of the eccentric pin 52 on the front side of the slider 53.
Therefore, the slider 53 is supported so as to be movable in the up-down direction along the slider guide 56. The upper end of a rod-shaped plunger 59 extending in the vertical direction is connected to the center of the lower end of the slider 53.
In this manner, a crank mechanism is formed inside the gear housing 10. In the crank mechanism, a crank disk 51 rotates together with the main shaft 50. Then, by the eccentric movement of the eccentric pin 52, the slider 53 reciprocates up and down by an amount corresponding to the amount of movement of the eccentric pin 52 in the up-down direction. Accordingly, the plunger 59 moves up and down.
A pump 60 is provided in the front holder 12 of the gear housing 10. The pump 60 discharges the grease supplied from the container 13 by the upward and downward movement of the plunger 59. The pump 60 includes an upper cylinder 61 and a lower cylinder 62. The upper tube portion 61 protrudes downward from the upper inner surface of the front holder 12. The lower tube portion 62 protrudes upward from the lower inner surface of the front holder 12 coaxially with the upper tube portion 61. A gap 63 communicating with the inside of the front holder 12 is formed between the upper tube portion 61 and the lower tube portion 62. The plunger 59 moves up and down through the upper cylinder 61 and the lower cylinder 62. At the top dead center of the plunger 59, the lower end of the plunger 59 is substantially retracted into the upper cylinder portion 61 above the gap 63. At the bottom dead center of the plunger 59, the lower end of the plunger 59 reaches a substantially middle portion in the lower cylinder portion 62. A vertical discharge passage 64 is formed in the lower cylinder 62. The longitudinal discharge passage 64 communicates with the gap 63 and through which the plunger 59 is inserted.
In the vertical discharge passage 64, a portion below the lower end of the plunger 59 at the bottom dead center is a large diameter passage 65 having a larger diameter than the insertion portion of the plunger 59. A lateral discharge passage 66 communicating with the large diameter passage 65 is formed forward in the lower cylinder portion 62. The grease discharge passage is formed by a vertical discharge passage 64 and a horizontal discharge passage 66 including a large diameter passage 65.
The lateral discharge passage 66 is constituted by an inner discharge passage 66a connected to the large-diameter passage 65 and an outer discharge passage 66b connected to the inner discharge passage 66a and opened to the front surface of the front holder 12. As shown in fig. 8 (B), the inner discharge passage 66a has an oval cross-sectional shape extending in the left-right direction, and passes through the lower tube portion 62 to communicate with the large diameter passage 65. The outer discharge passage 66b is formed coaxially with a front tube portion 67 formed on the front holder 12 and protruding forward. A hose 68 is connected to the front tube portion 67 in the forward direction. An air valve 69 is provided on the upper side of the hose 68 and on the front surface of the front holder 12. The air valve 69 releases the air inside to the outside, and eliminates a discharge failure due to the intrusion of air.
A check valve 70 is provided in the large diameter passage 65 of the vertical discharge passage 64. The check valve 70 is provided to prevent the grease from flowing backward from the large diameter passage 65. The check valve 70 includes a flat washer 71, a ball 72, a coil spring 73, and a retaining bolt 74. The flat washer 71 is provided on the inner surface of the upper end of the large diameter passage 65. The ball 72 can open and close the opening of the flat washer 71. The coil spring 73 biases the ball 72 to a valve-closing position where the opening of the flat washer 71 is closed. The holding bolt 74 holds the coil spring 73 and closes the lower portion of the large-diameter passage 65. The upper end of the holding bolt 74 is located below the opening of the inner discharge passage 66a of the lateral discharge passage 66, and does not prevent the communication between the large diameter passage 65 and the inner discharge passage 66 a.
As shown in fig. 5, the front holder 12 has a connection passage 75 formed on the right side of the front tube portion 67. The connection passage 75 includes an inner connection passage 76 connected to the outer discharge passage 66b of the lateral discharge passage 66, and an outer connection passage 77 connected to the inner connection passage 76 and opened on the right side surface of the front holder 12. As shown in fig. 8 (a), the inner connecting passage 76 has an oblong cross-sectional shape extending in the vertical direction, penetrates the front tube portion 67, and communicates with the outer discharge passage 66 b. The outer connecting passage 77 has a diameter longer than the major axis dimension of the inner connecting passage 76, and is internally threaded at the inner periphery.
A relief valve 80 is provided in the connection passage 75. The relief valve 80 is provided to release the grease to the outside when the pressure of the grease in the lateral discharge passage 66 increases.
As also shown in fig. 6, the relief valve 80 includes a valve bolt 81, a valve pin 82 provided in the valve bolt 81, a ball 83 held by the valve pin 82, a coil spring 84 for urging the valve pin 82, and a stopper screw 85 for preventing the coil spring 84 from coming off. The relief valve 80 is provided separately from the front holder 12 and is unitized.
The valve bolt 81 has a threaded portion 86 at its tip end and is screwed into the external connection passage 77. A relief flow passage 87 having a circular cross section and penetrating in the axial direction is formed in the valve bolt 81. The relief flow passage 87 includes a tip end flow passage 88 on the tip end side of the valve bolt 81, an intermediate flow passage 89 connected to the tip end flow passage 88 and having a larger diameter than the tip end flow passage 88, and a rear end flow passage 90 connected to the intermediate flow passage 89 and having a larger diameter than the intermediate flow passage 89. The intermediate flow path 89 is formed with discharge passages 91, 91 extending radially outward and opening to the side surface of the valve bolt 81. A cap-shaped bonnet 92 (fig. 4 and 5) is attached to the rear end of the valve bolt 81 including the openings of the discharge passages 91 and 91.
As shown in fig. 7, the tip inner surface of the intermediate flow passage 89 connected to the tip flow passage 88 is a tapered surface 93 that protrudes toward the tip flow passage 88 as it approaches the center. A spherical valve seat 94 is formed at the center (bottom) of the tapered surface 93 along the outer surface shape of the ball 83.
The valve pin 82 has: a pin main body 95 having a diameter slightly smaller than the intermediate flow path 89; and a shaft portion 96 that protrudes from the center of the pin body 95 toward the rear end flow path 90 side. The tip of the pin main body 95 is tapered toward the tip passage 88, and a receiving recess 97 is formed in the center. The balls 83 are fitted into the receiving recesses 97 and positioned and held.
As shown in fig. 6 (C), three grooves 98, 98 … … are formed at equal intervals in the circumferential direction on the outer periphery of the pin main body 95 over the entire length of the pin main body 95.
The coil spring 84 is externally fitted to the shaft portion 96, and the tip thereof abuts against the pin main body 95. The fixing screw 85 is screwed into the rear end flow path 90 to receive the rear end of the coil spring 84.
Therefore, the valve pin 82 is normally held at the valve-closing position where the ball 83 is seated on the valve seat 94 by the biasing force of the coil spring 84.
As shown in fig. 3, a switching valve 100 is provided on the left side surface of the front holder 12. The switching valve 100 has a main body 101. The main body 101 is screwed from the left side surface of the front holder 12 at the position of the lower tube portion 62 and projects into the front holder 12. The tip of the main body 101 is located in a large-diameter relief recess 102 provided in the left side surface of the lower tube portion 62. An internal flow path 103 open at the tip is formed at the axial center of the main body 101. The internal flow path 103 has a valve seat 104 in the middle. The switching pin 105 is housed in the internal flow passage 103 so as to be movable in the axial direction. The switching pin 105 holds a ball 106 that can be seated on the valve seat 104 at its tip. The switching pin 105 is biased by a coil spring 107 to a valve-closed position where the ball 106 is seated on the valve seat 104.
A lateral flow passage 108 is provided on the left side of the valve seat 104 at the distal end of the main body 101. The lateral flow passage 108 communicates with the internal flow passage 103 in a perpendicular manner, and opens at a side surface of the main body 101. The left end of the main body 101 protrudes toward the left side surface of the front holder 12 and is coupled to the operation knob 40.
The lower tube portion 62 is formed with a communication passage 109. A communication passage 109 is formed in the left-right direction on the upstream side of the balls 72 of the check valve 70, and communicates the vertical discharge passage 64 with the relief recess 102. The communication passage 109 faces the internal flow path 103 of the main body 101.
The switching valve 100 is configured to be capable of being moved by screwing with respect to the front holder 12 by a rotational operation of the body 101 by the operation knob 40. By the screw feed movement, the automatic switching position and the manual opening position of the switching valve 100 can be selected. The automatic switching position is a position where the distal end of the main body 101 abuts on the bottom surface of the relief recess 102 and the communication passage 109 communicates only with the internal flow path 103. The manual open position is a position where the top end of the main body 101 is separated from the bottom surface of the release recess 102. In the manual open position, the communication passage 109 opens into the release recess 102, and communicates from a gap with the main body 101 into the front holder 12.
When the automatic switching position is selected, the internal flow path 103 is closed by the ball 106 when the pressure transmitted from the vertical discharge path 64 and the communication path 109 to the internal flow path 103 is smaller than the biasing force of the coil spring 107. When the pressure on the internal flow path 103 exceeds the biasing force of the coil spring 107, the ball 106 is separated from the valve seat 104 against the biasing force of the coil spring 107, and the internal flow path 103 is opened. Therefore, the grease flowing into the internal passage 103 from the communication passage 109 is returned from the lateral passage 108 into the front holder 12, and the pressure in the vertical discharge passage 64 is released.
When the manual open position is selected, the main body 101 is separated from the bottom surface of the release recess 102, and thereby the grease in the vertical discharge passage 64 always flows out from the communication passage 109 into the front holder 12 via the release recess 102. The amount of release of the release recess 102 can be adjusted by setting the gap between the body 101 and the bottom surface of the release recess 102.
In any one of the automatic switching position and the manual opening position, by the switching valve 100, the discharge amount of the grease discharged can be changed (automatically in the automatic switching position, by manual adjustment in the manual opening position) with the number of reciprocating movements of the plunger 59 per unit time kept constant.
The container 13 is a bottomed cylinder having an open front surface. The container 13 is inserted through the front leg 15 and the rear leg 16 of the rear holder 14 of the main body case 2 from the rear, and the front end thereof is screwed to the front holder 12. In this state, the case 13 is coupled to the front holder 12 in a forward posture below the motor housing portion 4. A rod 115 having a piston 116 at its distal end is accommodated in the container 13 so as to be movable in the front-rear direction. The rear end of the lever 115 protrudes from the rear end of the container 13 and is provided with a handle 117. A coil spring 118 is provided behind the piston 116 in the container 13 to bias the piston 116 forward. A constricted portion 119 is provided on the outer periphery of the rod 115. When the rod 115 is retracted to lock the constricted portion 119 to the rear end of the container 13, the piston 116 can be positioned at a rear position in the container 13.
When a grease cartridge (not shown) filled with grease is accommodated in the container 13, the grease is pushed out from the grease cartridge pressed by the piston 116 and supplied to the pump 60, and the piston 116 advances by the biasing force of the coil spring 118.
In the grease gun 1 configured as described above, the trigger 21 is pushed in while the container 13 that houses the grease cartridge is coupled to the front holder 12. Then, the controller 30, which detects the signal for triggering the switch 20, supplies a drive current to the DC motor 8 to rotate the output shaft 9. The rotation of the output shaft 9 is reduced in speed by the reduction mechanism 11 and transmitted to the main shaft 50, so that the crank disc 51 rotates at a reduced speed together with the main shaft 50. Accordingly, the eccentric pin 52 eccentrically moves to move the slider 53 up and down, and the plunger 59 reciprocates up and down together with the slider 53. Therefore, in the pump 60, when the plunger 59 reaches the top dead center, grease flows into the vertical discharge passage 64 of the lower cylinder 62 from the gap 63 between the upper cylinder 61 and the lower cylinder 62. Thereafter, when the plunger 59 moves to the bottom dead center, the grease pushed downward in the vertical discharge passage 64 presses down the balls 72 of the check valve 70 and flows into the large diameter passage 65. Then, the grease flows from the large diameter passage 65 into the lateral discharge passage 66, and is directly discharged through the hose 68. This discharge operation is repeated with the reciprocation of the plunger 59.
The grease that has flowed into the lateral drain passage 66 also flows into the connection passage 75. If the grease pressure at this time does not exceed the biasing force of the coil spring 84 that causes the ball 83 to be seated on the valve seat 94 in the relief valve 80, the valve pin 82 does not retreat, and the relief valve 80 does not operate. On the other hand, when the pressure of the grease in the connection passage 75 exceeds the biasing force of the coil spring 84, the valve pin 82 is retracted against the biasing force of the coil spring 84, and the ball 83 is separated from the valve seat 94. Therefore, the grease in the connecting passage 75 flows from the tip end passage 88 of the relief passage 87 into the intermediate passage 89, and the pressure in the lateral discharge passage 66 is released.
After that, the valve pin 82 is advanced by the biasing force of the coil spring 84, and the ball 83 is again seated on the valve seat 94. At this time, since the front inner surface of the intermediate flow path 89 is the tapered surface 93, the ball 83 is smoothly guided to the central valve seat 94 without being eccentric. Further, even if the valve pin 82 repeats the forward and backward movement due to the pressure rise, the ball 83 is seated on the spherical valve seat 94, so that the surface pressure is reduced and the valve seat 94 is less likely to be damaged. Therefore, the operating pressure of the relief valve 80 does not vary.
The grease that has flowed into the intermediate flow path 89 is retained in a space S (fig. 7) between the valve pin 82 and the tapered surface 93, and then flows toward the rear end flow path 90 through a groove 98 provided on the outer periphery of the pin main body 95. Then, the exhaust path 91 exhausts the gas to the outside of the valve pin 82. Therefore, the increase of the internal pressure in the space S is suppressed, and the deviation of the operating pressure accompanying the increase of the internal pressure is also prevented.
On the other hand, when the pressure in the lateral discharge passage 66 and the connection passage 75 rises, a tensile force (stress) in the circumferential direction is generated in the lower cylinder portion 62 in which the inner discharge passage 66a is formed. Similarly, a tensile force (stress) is generated in the circumferential direction in the front tubular portion 67 in which the internal connection passage 76 is formed. However, since the cross-sectional shape of the inner discharge passage 66a is an oval shape extending laterally in the circumferential direction of the lower cylinder portion 62, stress concentration at the inner discharge passage 66a portion is alleviated. Similarly, since the cross-sectional shape of the internal connection passage 76 is also an oblong shape extending vertically in the circumferential direction of the front cylindrical portion 67, the stress concentration at the internal connection passage 76 portion is alleviated.
In the switching valve 100, when the automatic switching position is switched by the operation knob 40, the internal flow path 103 is closed by the ball 106 while the load pressure during the discharge operation is low and the pressure in the internal flow path 103 of the main body 101 is lower than the biasing force of the coil spring 107. Therefore, the grease discharged from the pump 60 becomes a high discharge amount (low pressure).
When the load pressure increases and the pressure in the internal flow passage 103 exceeds the biasing force of the coil spring 107, the ball 106 is separated from the valve seat 104 against the biasing force of the coil spring 107. Therefore, the grease flowing in from the communication passage 109 is returned from the lateral flow passage 108 to the front holder 12 through the internal flow passage 103, and the pressure in the vertical discharge passage 64 is released. The stroke of the plunger 59 is substantially halved by the operation of the switching valve 100, and therefore the grease discharged from the pump 60 is low in discharge amount (high pressure).
On the other hand, when the switching valve 100 is switched to the manual opening position, the communication passage 109 always communicates with the interior of the front holder 12 via the release recess 102. Therefore, since there is grease returned from the communication passage 109 into the front holder 12 via the relief recess 102, the amount of grease discharged from the pump 60 is low. This release amount can be changed according to the setting of the gap between the body 101 and the bottom surface of the release recess 102, and thus the degree of freedom of setting is improved.
As described above, the grease gun 1 according to the above embodiment includes the DC motor 8 (motor), the pump 60 that operates by driving the DC motor 8, the motor case portion 4 (motor case) that houses the DC motor 8, and the front holder 12 (pump case) that includes the pump 60. Further, the front holder 12 is formed with a vertical discharge passage 64 and a lateral discharge passage 66 (discharge passage) for grease discharged by the pump 60, and the lateral discharge passage 66 is provided with a relief valve 80 for releasing the pressure in the lateral discharge passage 66. Further, the relief valve 80 includes: an overflow passage 87 communicating with the lateral discharge passage 66; a valve pin 82 (valve body) slidable between a valve-closed position and a valve-open position of a valve seat 94 provided in the relief flow path 87; and a coil spring 84 (urging member) that urges the valve pin 82 to the valve-closing position. Further, a groove 98 (relief passage) is formed in the valve pin 82, and the groove 98 is used to relieve an internal pressure generated in the space S on the valve seat 94 side of the valve pin 82 to the opposite side of the valve seat 94 side of the valve pin 82.
With this structure, the valve pin 82 can operate without being affected by the internal pressure generated on the valve seat 94 side. Therefore, variation in the operating pressure of the relief valve 80 can be suppressed.
In particular, a groove 98 formed on the outer periphery of the valve pin 82 serves as a relief passage. Therefore, the relief passage can be simply formed.
The groove 98 is formed in plural. Therefore, the internal pressure can be reliably released.
The valve pin 82 has a ball 83 which is seated on a valve seat 94 at a valve-closing position, and the valve seat 94 has a spherical shape along the outer surface shape of the ball 83. Therefore, the surface pressure against the valve seat 94 is reduced, thereby preventing deformation or damage of the valve seat 94. This suppresses variation in the operating pressure due to deformation of the valve seat 94 and the like.
The outer side of the valve seat 94 in the intermediate flow path 89 of the relief flow path 87 is a tapered surface 93 having the valve seat 94 as a bottom. Therefore, when the ball 83 closes, the ball 83 abuts against the tapered surface 93 and is guided (aligned) toward the valve seat 94, and variation in the operating pressure due to eccentricity of the ball 83 is suppressed.
On the other hand, the cross-sectional shape of the interconnecting passage 76 of the connecting passage 75 connecting the relief valve 80 is an oblong extending in the circumferential direction of the front cylindrical portion 67 (outlet cylindrical portion).
The cross-sectional shape of the inner discharge passage 66a in the front cylinder portion 67 connected to the lower cylinder portion 62 (pressure-feed cylinder portion) is an oval shape extending in the circumferential direction of the lower cylinder portion 62.
Therefore, the concentration of stress on the front cylinder portion 67 and the lower cylinder portion 62, which is generated along with the formation of the inner connecting passage 76 and the inner discharge passage 66a, is alleviated, and the pressure resistance is improved.
Here, the kind of the pump is not limited. In the embodiment, a pump using a reciprocating plunger is used. However, other types of pumps may be used. For example, a centrifugal pump (a pump that applies pressure to grease by centrifugal force applied in a radial direction), an axial pump (a pump that applies pressure to grease by pressure applied in an axial direction), and a jet pump (a pump that applies pressure to grease by pressure applied in an oblique direction) may be used. Further, a gear pump, a screw pump, or other types of pumps are also possible. In any of the pumps, since the pressure is applied to the pump via the grease, the stress concentration caused by the pressure can be alleviated.
Further, the number and positions of the grooves provided on the valve pin are not limited to the above. The width of the slot may also vary. The shape of the valve pin may also be varied. Instead of the ball, a pin with a spherical tip may be held on the valve pin.
The relief passage is not limited to the groove, and may be a through hole that penetrates the valve pin and opens in the front and rear of the pin body.
The position where the relief valve is provided is not limited to the above. For example, the left side surface or the lower surface of the front holder may be provided. The valve pin or the like may be mounted on the front holder in which the relief flow path is formed, without being limited to the unitization.
In the above embodiment, in order to suppress variation in the operating pressure of the relief valve, a spherical valve seat and a tapered valve seat outside are used. However, the present invention is not limited thereto, and either one or both of these structures may be omitted.
In addition, the cross-sectional shapes of the connection passage and the discharge passage are not limited to the oblong shapes, and an elliptical shape may be used.
The motor may be a brushless motor.
The motor housing and the handle portion may be formed in the vertical direction by supporting the container in the vertical direction instead of the front-rear direction.
The housing is not limited to the above-described manner in which the motor housing, the handle portion, and the like are integrally formed. For example, a plurality of separate housings formed separately may be connected to each other to form a housing.
The battery pack may be plural. Or an AC machine that does not use a battery pack.

Claims (14)

1. A grease discharging device is characterized in that,
the method comprises the following steps: a motor; a pump that is operated by driving of the motor; a motor housing that houses the motor; and a pump housing having the pump,
a discharge passage for the grease discharged by the pump is formed in the pump housing,
a relief valve for relieving pressure in the discharge passage is provided in the discharge passage,
the relief valve has: an overflow flow path communicating with the discharge passage; a valve body that is slidable between a valve-closed position and a valve-open position of a valve seat provided in the relief flow path; and a biasing member that biases the valve element to the valve-closed position,
the valve body is formed with a release passage for releasing the inward pressure generated on the valve seat side relative to the valve body toward the side opposite to the valve seat relative to the valve body.
2. Grease discharge device according to claim 1,
the relief passage is a groove formed on an outer periphery of the valve element.
3. Grease discharge device according to claim 2,
the groove is formed in plurality.
4. A grease discharging device according to any one of claims 1 to 3,
the valve element has a ball seated on the valve seat in the valve-closed position,
the valve seat is spherical in shape along the outer surface of the ball.
5. Grease discharge device according to claim 4,
the outer side of the valve seat in the overflow flow path is a conical surface with the valve seat as a bottom.
6. Grease discharge device according to claim 1,
the urging member is a coil spring.
7. Grease discharge device according to claim 1,
the pump includes: a plunger that reciprocates by the driving of the motor; and a pressure feed cylinder portion into which the plunger is inserted and removed,
an outlet cylinder portion formed to protrude from the pump housing is connected to the pressure-feed cylinder portion,
the discharge passage is formed inside the pressure-feed cylinder and the outlet cylinder.
8. Grease discharge device according to claim 7,
a connection passage communicating with the outlet cylinder is formed in the pump housing,
the relief valve is connected to the connection passage in a split unit manner, and the relief flow path is communicated with the connection passage.
9. Grease discharge device according to claim 8,
the cross-sectional shape of the connection passage is an oblong or elliptical shape extending in the circumferential direction of the outlet cylinder.
10. The grease discharging device according to any one of claims 7 to 9,
the cross-sectional shape of the discharge passage in the outlet cylinder connected to the pressure-feed cylinder is an oblong or elliptical shape extending in the circumferential direction of the pressure-feed cylinder.
11. Grease discharge device according to claim 7,
the plunger and the pressure-feed cylinder are disposed in the vertical direction, and the outlet cylinder protrudes forward.
12. Grease discharge device according to claim 11,
the motor housing is disposed above the pump housing, and an annular handle portion is provided above the motor housing in the front-rear direction.
13. Grease discharge device according to claim 12,
the rear end of the handle part is provided with a mounting part of the battery pack.
14. Grease discharge device according to claim 7,
a reservoir for supplying grease to the pump is connected to the pump housing in the front-rear direction.
CN202022090934.2U 2019-12-25 2020-09-22 Grease discharging device Active CN214008811U (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019-234791 2019-12-25
JP2019234791A JP7458182B2 (en) 2019-12-25 2019-12-25 Grease Dispensing Device

Publications (1)

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CN214008811U true CN214008811U (en) 2021-08-20

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Application Number Title Priority Date Filing Date
CN202022090934.2U Active CN214008811U (en) 2019-12-25 2020-09-22 Grease discharging device

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JP (1) JP7458182B2 (en)
CN (1) CN214008811U (en)
DE (1) DE202020107145U1 (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60123467U (en) * 1984-01-27 1985-08-20 株式会社アツギユニシア pressure control valve
JP2008025734A (en) * 2006-07-21 2008-02-07 Hitachi Powdered Metals Co Ltd Relief valve
JP2019203463A (en) * 2018-05-24 2019-11-28 株式会社マキタ Grease discharge device

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DE202020107145U1 (en) 2021-01-12
JP7458182B2 (en) 2024-03-29

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