JP2005179976A - Forward movement/backward movement switching hand pump for vibration compaction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forward movement/backward movement switching hand pump for a vibration compaction machine, which is activated by moving a hand pump operating lever to an arbitrary forward or backward position by the operator, and thereafter automatically holds a set position without arbitrary movement of the lever even if the operator takes off the hand from the operating lever, to thereby carry out traveling thereof at a safe speed according to the set position. <P>SOLUTION: According to the structure of the hand pump, a servo rod 34 which carries out reciprocating motion upon rotation of the operating lever 30, is slidably inserted into a cylinder tube 27 via the interior of a plug 37 equipped with a check valve, which is arranged between an oil tank 25a and the cylinder tube, and a cylinder piston 28 is mounted on the tip of the servo rod 34. Further, pressure chambers 40, 41 for storing and preserving therein pressure oil in an amount necessary for holding a rotational angle of the frontward movement/backward movement operating lever 30 are arranged at front and rear locations of the cylinder piston 28. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to forward / reverse switching in a vibration compacting machine that changes the phase of rotation of one eccentric pendulum with respect to the other eccentric pendulum of a pair of eccentric pendulums in a vibration generator and moves the body forward and backward by the resultant vector. It relates to the improvement of the hand pump.

  Conventionally, a vibration compacting machine of this type that changes the rotation phase of one eccentric pendulum with respect to the other eccentric pendulum of a pair of eccentric pendulums in a vibration generator and gives the aircraft forward and backward movement by the resultant vector. As the forward / reverse switching mechanism, the rotation of the forward / reverse lever is transmitted to the rotation switching mechanism of the eccentric pendulum by mechanical means via a link or cable, and the hydraulic power is generated by the rotation of the forward / backward lever. What is transmitted to the rotation switching mechanism of the eccentric pendulum by the hydraulic power means is known, and those that use the hydraulic power means are disclosed in, for example, Patent Document 1 to Patent Document 10.

  Of the above, those using hydraulic power for the forward / reverse switching mechanism of the vibration compactor are those that are provided on the hydraulic cylinder of the forward / reverse switching shaft that changes the phase of the eccentric pendulum in the vibration generator and the forward / reverse travel provided on the handle of the fuselage. A hydraulic hose is connected to the forward / reverse switching hand pump having a lever, and the piston in the forward / reverse switching hand pump is moved by operating the forward / reverse lever to pump the hydraulic cylinder of the forward / reverse switching shaft in the vibration generator. Tell the hydraulic pressure of the side.

Japanese Examined Patent Publication No. 61-48997 Japanese Unexamined Patent Publication No. 63-60306 Japanese Patent Publication No. 5-17323 JP-A-6-33413 JP 7-286306 A JP-A-11-222805 Japanese Patent Laid-Open No. 11-323817 JP 2000-17607 A JP 2002-317405 A JP 2002-339313 A

  In this type of conventional vibration compactor, the mechanical return force is transmitted from the direction of the hydraulic cylinder of the forward / reverse switching shaft in the vibration generator to the direction of the forward / reverse switching hand pump. When the operator sets the operation lever of the forward / reverse switching hand pump to the forward or reverse side, the rotation phase of one eccentric pendulum in the vibration generating device is changed, thereby obtaining the forward force and the reverse force of the airframe. It is like that.

  Therefore, after the vibration generator is driven to rotate and the operator moves the operation lever of the forward / reverse switching hand pump to a certain position in the forward or reverse direction, the position must be held and held by hand. The forward / reverse switching hand pump receives a mechanical return force from the hydraulic cylinder direction of the forward / reverse switching shaft in the vibration generator, automatically travels forward or backward, and then travels at the fastest state. There was a problem that a dangerous situation occurred.

  For this reason, conventionally, when the vibration compactor is operated, the vibration generator is driven to rotate, and after the operator moves the operation lever of the forward / reverse switching hand pump in the forward or reverse direction, it is a safety aspect. The operator has been instructed not to let go of the hand pump operating lever.

  However, when operating the vibration compactor, it is also necessary for safety reasons that the operator does not release the operation lever after moving the operation lever of the forward / reverse switching hand pump in the forward or reverse direction. Although it may be that, as another view, even if the operator moves the operation lever of the forward / reverse switching hand pump to the desired forward or reverse position, the aircraft does not If it is structured so that it can automatically run safely at a fixed speed at the position where the control lever is set without running away, the operator releases the control lever and moves to another aircraft operation. It has the advantage that attention can be paid and high quality vibration compaction work can be expected.

  From this point of view, in the past, in order to ensure the safety of traveling even if an operator releases the operating lever while the aircraft is traveling, a friction plate is provided by a spring on the rotating shaft portion of the operating lever. In order to prevent the operating lever from rotating freely due to frictional force, this measure does not stabilize the spring tightening force, and the spring tightening force is always periodically increased. It was not an appropriate solution because it had to be adjusted.

  The present invention does not release the operation lever during operation after the operator operates the operation lever of the forward / reverse switching hand pump in either the forward or backward direction, such as a conventional vibration compactor. This eliminates the problem that the position must be held by hand, and after the operator moves the hand pump operating lever to any position in the forward / backward direction, move the hand from the operating lever at that position. The purpose is to provide a forward / reverse switching hand pump in a vibration compactor that automatically holds the set position without moving the lever even if it is released, and can run at a safe speed according to the set position. It is what.

  The forward / reverse switching hand pump of the vibration compactor according to the present invention has a connecting end connected to the hydraulic cylinder of the forward / reverse switching shaft in the vibration generator at one end in the cylinder tube connected to the pump body as means for that purpose. In addition, a plug with a check valve is placed at the other end between the oil tank in the pump body, and the cylinder tube is moved horizontally by the forward / backward operation lever pivoted in the pump body. A servo rod having a valve and a flow path that reciprocally moves to the oil tank through the inside of the shaft and flows out into the oil tank is slidably inserted into the plug, and the tip of the servo rod is It is inserted into the cylinder piston, and the rotation angle of the forward / reverse operation lever is maintained between the cylinder piston and the connecting end and between the cylinder piston and the plug with check valve. And it is characterized in that it comprises a pressure chamber capable of storing holding pressure oil required amount.

  The pressure chambers provided on both sides of the cylinder piston in the cylinder tube include a front pressure chamber that receives pressure oil supplied with a mechanical return force sent from the direction of the hydraulic cylinder of the vibration generator on the front side of the cylinder piston, and a cylinder It is preferable that the rear side of the piston has a structure including a rear pressure chamber that receives the pressure oil that passes through the check valve of the plug and is sent from the oil tank in the pump body.

  The tip of the servo rod inserted into the cylinder piston is given a spring force that pulls it back in the cylinder piston when the servo rod is pulled in the pump body direction. The end inner peripheral part is equipped with a flow hole that leads from the outer peripheral surface to the flow path in the shaft, and a poppet valve that joins the valve seat of the inner peripheral part of the rear end of the cylinder piston on the outer peripheral surface adjacent to this flow hole. When the servo rod is pulled in the direction of the pump body, the poppet valve moves away from the valve seat, and the hydraulic oil in the rear pressure chamber flows out from the flow hole of the servo rod to the oil tank in the pump body through the flow path in the shaft. It is preferable to do so.

  A steel ball is placed on the tip of the servo rod that is inserted inside the cylinder piston, and a cylindrical valve seat is placed on the front end surface in contact with the front pressure chamber of the cylinder piston. It is inserted into the front end surface of the cylinder piston so that it can be moved by the amount of movement of the cylinder, and is in contact with the steel ball at the tip of the servo rod. When the flow path to the inside is shut off and the servo rod is moved to a position exceeding the predetermined movement amount of the cylindrical valve seat, the cylindrical valve seat and the steel ball are separated, and the front pressure chamber and the cylinder piston communicate with each other. In addition, it is preferable to provide an air bleeding mechanism that can discharge the bubbles in the front pressure chamber to the oil tank in the pump body.

  In the forward / reverse switching hand pump according to the present invention, the cylinder piston is disposed at the tip of the servo rod that reciprocates by the rotation of the forward / reverse operation lever in the cylinder tube, and the front / rear positions of the front / rear side of the cylinder piston are respectively A front pressure chamber and a rear pressure chamber are provided that can store and hold the amount of pressure oil required to hold the rotation angle of the advance operation lever, so that the pressure oil is stored not only in the neutral state but also during forward and reverse travel. Even if the volume of the chamber is different, the balance of pressure in each pressure chamber is balanced, so even if you release your hand from the operation lever, the aircraft will safely run at the desired speed set by the lever. Can do.

  In addition, in the conventional vibration compaction machine of this type, it is necessary to increase the pressure for operating the operation lever when the body weight increases. Therefore, in the case of a heavy body, a hydraulic pump is used as a hand pump. However, according to the present invention, the operation lever is provided with pressure chambers with balanced pressure balance on both sides of the cylinder piston. The lever can be operated from a balanced position of the pressure balance. Therefore, even a heavy aircraft does not require an auxiliary part such as a power booster, and an inexpensive and easy-to-operate aircraft can be provided.

  Further, in the apparatus of the present invention, since the air vent mechanism that can discharge the air bubbles in the front pressure chamber to the oil tank in the pump body is provided on the front end surface of the cylinder piston, the air bubbles generated in the pump during traveling are effective. Therefore, it is possible to prevent the occurrence of danger and to expect safe work.

  The present invention is provided with pressure chambers on both the front and rear sides of the cylinder piston arranged in the cylinder tube for storing and holding the pressure oil amount necessary for holding the rotation angle of the forward / reverse operation lever. In addition to this, the aircraft has the advantage of being able to travel safely at the speed at which the lever is set, even if the lever is released from the control lever. Since air bubbles generated in the inside can be removed, a mode in which this air venting mechanism is additionally provided in the implementation is preferable.

  Next, the configuration of the forward / reverse switching hand pump according to the present invention will be described with reference to the embodiment shown in the drawings. The forward / reverse switching hand pump 2 is arranged at the rear of the vibration compactor 1 as shown in FIGS. 3 and is connected to a hydraulic cylinder 23 provided at one end of a forward / reverse switching shaft 17 in the vibration generator 4 shown in FIG. 3 via a hydraulic hose 5. .

As shown in FIG. 3, the vibration generator 4 has a drive shaft 8 that can transmit rotation from the engine 6 of FIG. 2 via a pulley 7, and a driven shaft 9 that is arranged in parallel to the drive shaft 8. An eccentric pendulum 10 is fixed to the drive shaft 8, and a similar eccentric pendulum 11 is mounted on the driven shaft 9 so that the phase can be changed with respect to the drive shaft eccentric pendulum 10. .

  A central portion of the driven shaft 9 is provided with a driven gear 13 that is rotatable with respect to the shaft 9 and is mounted so as not to move in the axial direction. The driven gear 13 is a central portion of the drive shaft 8. The rotation is transmitted from the drive gear 12 fixed to the motor. The driven gear 13 is provided with a spiral groove 15 inclined on the inner wall of the boss 14 with respect to the axis of the boss 14.

On the other hand, the driven shaft 9 has a cylindrical shape, and in the portion where the driven gear 13 is located, elongated holes 16 are formed in the axial walls of the opposing shaft walls in the axial direction, respectively. In the inner part 9, a forward / reverse switching shaft 17 is inserted so as to be rotatable and movable in the axial direction.

  The forward / reverse switching shaft 17 has a large-diameter portion 18 that slides with the inner diameter of the driven shaft 9 and a small-diameter portion 19 that projects from one end of the large-diameter portion 18. A piston 20 is provided via 21, and this piston 20 is inserted into a hydraulic cylinder 23 provided at one end of a vibration body case 22 positioned on the axis of the driven shaft 9.

  Further, a pin 24 is embedded in the large-diameter portion 18 of the forward / reverse switching axis 17 so as to be orthogonal to the axial direction of the switching axis 17, and both ends of the pin 24 have the long holes 16 of the driven shaft 9. It penetrates and engages in a spiral groove 15 in the inner wall of the driven shaft 9.

  In a state where no external oil pressure acts in the hydraulic cylinder 23 in which the piston 20 at one end of the forward / reverse switching shaft 17 is inserted, if rotation from the drive gear 12 is transmitted to the driven gear 13, The lead switching shaft 17 is such that both ends of the pin 24 pass through the long hole 16 of the driven shaft 9 and engage with the spiral groove 15 on the inner wall of the driven gear 13. According to the direction and the rotational direction of the driven gear 13, a mechanical return force that is pushed in the left direction in FIG. When the forward / reverse switching shaft 17 is moved to the leftmost side in the drawing, the eccentric pendulum 11 of the driven shaft 9 is moved forward or backward with respect to the eccentric pendulum 10 of the drive shaft 8, for example, to the position where it travels at the fastest forward speed. It will be rotated.

  On the other hand, the hydraulic cylinder 23 in which the piston 20 at one end of the forward / reverse switching shaft 17 is inserted is connected to the front end connection port 26 of the forward / reverse switching hand pump 2 provided outside via the hose 5. The forward / reverse switching hand pump 2 is configured so that the forward / reverse switching shaft 17 in the driven shaft 9 receives a mechanical return force in the left direction by the spiral groove 15 of the driven gear 13, thereby 5 has a function of transmitting a mechanical return force through 5 and overcoming the mechanical return force to push back the forward / reverse switching shaft 17 in the opposite right (reverse) direction of FIG.

  As shown in FIG. 2, the forward / reverse switching hand pump 2 is provided in a pump body 25 attached to the upper end of the operation handle 3 of the machine body. As shown in FIG. An oil tank 25a provided on the right side of FIG. 1, a cylinder tube 27 that is connected to the oil tank 25a to form the center of the body, and a cylinder piston 28 that is inserted into the cylinder tube 27; A piping port 26 is connected to a connection end 29 provided at the tip (left side of FIG. 1) of the cylinder tube 27, and the piping port 26 and the hydraulic cylinder 23 of the vibration generator 4 are electrically connected via the hose 5. Yes.

  In the oil tank 25a, a rotation shaft 31 of a forward / reverse operation lever 30 is provided in a direction perpendicular to the axial direction of the cylinder tube 27, and the cam 32 fixed to the rotation shaft 31 is attached to the upper end of the cam 32. A hook 33 provided at the rear end of the servo rod 34 disposed in the cylinder tube 27 is connected so as to be rotatable, and the operation lever 30 is rotated between the forward position and the reverse position shown in FIG. The servo rod 34 reciprocates in the cylinder tube 27.

  In addition, a stopper arm 35 is provided at both sides of the rotation shaft 31 and a stopper pin 36 is provided below the rotation shaft 31. The rotation shaft 31 rotates in either direction to stop the rotation. When the arm 35 comes into contact with the stopper pin 36, the operation lever 30 is configured not to further rotate.

  At the connecting portion between the oil tank 25a and the cylinder tube 27, there is a plug 37 with a check valve provided with a suction port 38 on the oil tank 25a side and a check valve 39 that opens the suction port 38 by pressure from the oil tank 25a direction. The tip of the servo rod 34 provided at one end to the lever rotating shaft 31 in the oil tank 25a is slidably inserted into the plug 37 with a check valve so as to be centered in the cylinder tube 27. Extends in the direction.

  As shown in FIG. 1, in the state where the operation lever 30 is set to the neutral position, the tip of the servo rod 34 is located at the center of the cylinder tube 27, and the cylinder piston 28 is located at the tip of the servo rod 34. The cylinder tube 27 is provided with a pair of front pressure chambers 40 and rear pressure chambers 41 having the same volume on both sides of the cylinder piston 28, and the front pressure chamber 40 is shown in FIG. Pressure oil by a mechanical return force is fed from a hydraulic cylinder 23 of the vibration generator 4 shown.

  The servo rod 34 has a flow path 42 in the shaft extending from the lever rotation shaft 31 side in the oil tank 25a to the insertion portion in the cylinder piston 28. The oil tank 25a is provided in the flow path 42. A flow hole 43 that communicates with the inside, a flow hole 44 that communicates with the inner back part of the cylinder piston 28, and a rear end inner peripheral portion of the cylinder piston 28, which is normally closed by the inner peripheral surface of the piston rear end. A hole 45 is provided.

  The front end surface 28a of the cylinder piston 28 is provided with a window hole 46 communicating with the front pressure chamber 40, and the outer periphery of the servo rod 34 is communicated with the window hole 46 inside the piston. A flow path 47 is provided between the surface and the flow path 47 and the flow hole 44 communicating with the inner back of the servo rod 34 is configured to communicate with the surface.

  A steel ball 51 is disposed at the tip of the servo rod 34, and a spring 49 is disposed between the flange 48 and the inner rear end of the cylinder piston 28 at the outer periphery of the tip, so that the servo rod 34 is connected to the pump body. When pulled in the 25 direction, a spring force is applied by the spring 49 so that the servo rod 34 is pulled back in the cylinder piston 28.

  Further, a poppet valve 50 that closes with the piston rear end surface 28 b as a valve seat is provided on the outer peripheral surface of the servo rod 34 on the rear end side (pump body 25 side) of the cylinder piston 28. When the servo rod 34 is pulled in the direction of the pump body 25 against the spring force of the spring 49, the poppet valve 50 is slightly separated from the valve seat of the piston rear end face 28b, and the inside of the rear pressure chamber 38 is The pressure oil is configured to flow out from the flow hole 45 into the oil tank 25 a through the flow path 42 in the servo rod 34.

  As described above, the front end surface 28a of the cylinder piston 28 is provided with the window hole 46 communicating with the front pressure chamber 40, and the steel ball 51 is disposed at the tip of the servo rod 34 inside. A cylindrical valve seat 52 is provided in the window hole 46 so as to be moved by a predetermined amount of movement inward of the cylinder piston 28 by a spring 53, and the rear end of the cylindrical valve seat 52 is the cylinder piston 28. The front pressure chamber 40 and the flow path 47 in the cylinder piston 28 are blocked by contact with the steel ball 51 at the tip of the servo rod 34 inside.

  The cylindrical valve seat 52 is maintained in contact with the steel ball 51 in the cylinder piston 28 by the spring 53 disposed in the window hole 46 until the flange 54 at the front end reaches the position of the rear locking plate 55. Then, the front pressure chamber 40 and the flow path 47 in the cylinder piston 28 are blocked, but after the valve seat flange 54 moves to a position where it hits the rear locking plate 55, the servo rod 34 further moves in the reverse direction ( The steel ball 51 is separated from the cylindrical valve seat 52 by being pulled in the direction of the pump body 25).

  As a result, the front pressure chamber 40, the flow path 47 in the cylinder piston 28, the in-axis flow path 42 of the servo rod 34, and the oil tank 25a are electrically connected to each other, and bubbles in the front pressure chamber 40 are transferred to the oil tank 25a. It is discharged inside.

  Next, when the operation is described, as shown in FIGS. 1 and 4, when the forward / reverse operation lever 30 is set to the neutral position, the cylinder piston 28 is located at the center in the cylinder tube 27. 40 and the rear pressure chamber 41 have the same volume and receive a mechanical return force from the hydraulic cylinder 23 of the vibration generator 4 in the front pressure chamber 40 in front of the cylinder piston, but the rear pressure in the rear of the cylinder piston 28. Since the pressure oil in the chamber 41 is closed in the check valve 39 of the plug 37 between the oil tank 25a and does not flow into the oil tank 25a, the volumes of the front pressure chamber 40 and the rear pressure chamber 41 are equal. Maintained.

  As shown in FIG. 4, the steel ball 51 at the tip of the servo rod 34 is in contact with a cylindrical valve seat 52 provided on the front end surface of the cylinder piston 28, so that the pressure oil in the front pressure chamber 40 is cylinder It does not flow into the piston 28. Therefore, the pressure oil in the rear pressure chamber 41 backs up the cylinder piston 28 from the rear with respect to the front pressure chamber 40 that receives the mechanical return force from the hydraulic cylinder 23 of the vibration generating device 4, and the operation lever Even if 30 is held in the neutral position and the hand is released from the operation lever 30, the aircraft is still in the neutral position.

  On the other hand, as shown in FIG. 5, when the operation lever 30 is moved to an arbitrary set position in the forward direction, the servo rod 34 moves in the forward direction and compresses the front pressure chamber 40 at the front end surface of the cylinder piston 28. The volume in the front pressure chamber 40 is reduced, whereas the volume in the rear pressure chamber 41 is increased. Therefore, the check valve 39 of the plug 37 between the oil tank 25a is opened and the pressure from the rear oil tank 25a is increased. The oil flows into the rear pressure chamber 41, the pressure oil force in the front and rear pressure chambers 40, 41 is kept even, and the state is maintained even when the hand is released from the forward / reverse operation lever 30, and the aircraft Auto travels at the set speed of the lever setting position.

  As shown in FIG. 6, the servo rod 34 receives a moving force toward the front pressure chamber 40 in a state where the steel ball 51 at the tip is in contact with the cylindrical valve seat 52 provided on the front end surface of the cylinder piston 28. The pressure oil in the front pressure chamber 40 does not flow into the cylinder piston 28.

  As shown in FIG. 7, when the operation lever 30 is moved to an arbitrary set position in the reverse direction, the servo rod 34 is pulled in the reverse direction, and the rear end surface of the cylinder piston 28 compresses the inside of the rear pressure chamber 41. However, since the check valve 39 of the plug 37 between the oil tank 25a is closed, the pressure oil in the rear pressure chamber 41 does not flow out toward the oil tank 25a.

  When the servo rod 34 is further pulled backward in this state, the poppet valve 50 adjacent to the inner peripheral surface portion of the cylinder piston 28 at the servo rod 34 is disengaged from the piston rear end surface 28b as shown in FIG. The pressure oil in the pressure chamber 41 flows from the flow hole 45 through the flow path 42 in the axis of the servo rod 34 toward the oil tank 25a, the volume in the rear pressure chamber 41 is reduced, and the volume in the front pressure chamber 40 is increased. The pressure oil having a mechanical return force from the hydraulic cylinder 23 of the vibration generating device 4 flows into.

  However, when the reverse position of the control lever is stopped at a target position and the state where the servo rod 34 is pulled is stopped, the servo rod 34 is pulled back inward by the spring 49 to the cylinder piston 28, thereby Since the poppet valve 50 is closed to the piston rear end face 28b, the pressure oil in the rear pressure chamber 41 does not flow toward the oil tank 25a, and the pressure in the rear pressure chamber 41 and the pressure in the front pressure chamber 40 are balanced. Are maintained in a balanced state, and the state is maintained even when the hand is released from the forward / reverse operation lever 30, and the aircraft automatically travels at the set speed of the lever set position.

  When the servo rod 34 is moved in the reverse direction, as shown in FIG. 8, the poppet valve 50 is opened by moving the servo rod 34 in the right direction. At this time, the steel ball 51 at the tip of the servo rod 34 Since the state of contact with the cylindrical valve seat 52 is maintained until the flange 54 of the cylindrical valve seat 52 hits the locking plate 55, the pressure oil in the front pressure chamber 40 does not flow inward in the cylinder piston 28 but moves backward. Move in the direction.

  Since air bubbles may be generated in the front pressure chamber 40, in order to remove the mixed air, as shown in FIG. 9, after moving the operating lever 30 to the most backward reverse position, a further small amount is required. Only move in the reverse direction. Then, as shown in FIG. 10, the spring 53 pushing the cylindrical valve seat 52 extends to the longest position, and the cylindrical valve seat 52 does not extend any further, so that the steel ball 51 is detached from the cylindrical valve seat 52. As a result, the pressure oil in the front pressure chamber 40 enters the cylinder piston 28 and flows from the flow hole 44 of the servo rod 34 to the oil tank through the in-axis flow path 42. As a result, the bubbles contained in the front pressure chamber Can be discharged into the oil tank 25a.

  In the vibration compaction machine of the present invention, it is not necessary to incorporate auxiliary parts such as a power booster using a hydraulic pump even in the case of a heavy machine body, so it is possible to provide an inexpensive and easy-to-operate machine body. The availability can be very high.

Sectional drawing which shows the structure in the neutral state of the forward / reverse switching hand pump according to the present invention. The side view of a vibration compaction machine provided with this forward / reverse switching hand pump. The top view which shows the structure of the vibration generator in a vibration compaction machine. The expanded sectional view of the principal part in a neutral state. Sectional drawing which shows the structure in the advance state of the hand pump of this invention. The expanded sectional view of the important section in the advance state. Sectional drawing which shows the structure in the reverse drive state of the hand pump of this invention. The expanded sectional view of the principal part in a reverse drive state. Sectional drawing which shows the structure in the air bleeding state of the hand pump of this invention. The expanded sectional view of the principal part in an air bleeding state.

Explanation of symbols

1: Vibration compaction machine,
2: Forward / reverse switching hand pump,
3: Operation handle,
4: Vibration generator,
5: Hydraulic hose,
6: Engine,
7: pulley,
8: Drive shaft,
9: driven shaft,
10: Eccentric pendulum,
11: Eccentric pendulum,
12: Drive gear,
13: driven gear,
14: Boss
15: Spiral groove,
16: long hole,
17: Forward / reverse switching axis,
18: Large diameter part,
19: Small section
20: piston,
21: bearing,
22: Vibration body case,
23: hydraulic cylinder,
24: Pin,
25: Pump body,
25a: oil tank,
26: piping port,
27: cylinder tube,
28: cylinder piston,
29: Connection end 30: Operation lever,
31: Rotating shaft,
32: Cam
33: hook,
34: Servo rod,
35: Stopper arm,
36: Stopper pin,
37: Plug with check valve,
38: Suction port 39: Check valve,
40: Front pressure chamber,
41: rear pressure chamber,
42: Servo rod flow path,
43, 44, 45 ,: flow hole ,:
46: Window hole,
47: flow path in piston
48: flange,
49; Spring,
50: Poppet valve,
51: Steel ball,
52: cylindrical valve seat,
53: Spring,
54: flange,
55: Locking plate

Claims (4)

A forward / reverse switching hand pump for feeding pressure oil for forward / reverse switching to a hydraulic cylinder provided at one end of a forward / reverse switching shaft in a vibration generator, wherein one end in a cylinder tube connected to a pump body A connecting end to be connected to the hydraulic cylinder of the vibration generator is provided, and a plug with a check valve is arranged between the oil tank in the pump body at the other end,
The cylinder tube is provided with a valve and a flow path for reciprocating in the horizontal direction by the rotation of a forward / reverse operation lever pivotally supported in the pump body, and for allowing off-shaft pressure oil to flow out into the oil tank through the shaft. The servo rod is slidably inserted into the plug, and the tip of the servo rod is inserted into the cylinder piston.
A pressure chamber is provided between the cylinder piston and the connection end and between the cylinder piston and the plug with the check valve, respectively, for storing and holding the amount of pressure oil necessary for holding the rotation angle of the forward / reverse operation lever. A forward / reverse switching hand pump for vibration compaction machines.   A pressure chamber provided on both sides of the cylinder piston in the cylinder tube, on the front side of the cylinder piston, receiving a pressure oil to which a mechanical return force sent from the direction of the hydraulic cylinder of the vibration generator is applied, and a cylinder 2. The forward / reverse switching hand pump for a vibration compactor according to claim 1, further comprising a rear pressure chamber for receiving pressure oil sent from an oil tank in the pump body through a check valve of the plug on the rear side of the piston.   The tip of the servo rod inserted into the cylinder piston is given a spring force that pulls it back in the cylinder piston when the servo rod is pulled in the pump body direction. The end inner peripheral part is equipped with a flow hole that leads from the outer peripheral surface to the flow path in the shaft, and a poppet valve that joins the valve seat of the inner peripheral part of the rear end of the cylinder piston on the outer peripheral surface adjacent to this flow hole. When the servo rod is pulled in the direction of the pump body, the poppet valve moves away from the valve seat, and the hydraulic oil in the rear pressure chamber flows out from the flow hole of the servo rod to the oil tank in the pump body through the flow path in the shaft. The forward / reverse switching hand pump of the vibration compacting machine according to claim 1, wherein:   A steel ball is placed on the tip of the servo rod that is inserted inside the cylinder piston, and a cylindrical valve seat is placed on the front end surface in contact with the front pressure chamber of the cylinder piston. It is inserted into the front end surface of the cylinder piston so that it can be moved by the amount of movement of the cylinder, and is in contact with the steel ball at the tip of the servo rod. When the flow path to the inside is shut off and the servo rod is moved to a position exceeding the predetermined movement amount of the cylindrical valve seat, the cylindrical valve seat and the steel ball are separated, and the front pressure chamber and the cylinder piston communicate with each other. The forward / reverse switching hand pump of the vibration compactor according to claim 1, further comprising an air venting mechanism capable of discharging air bubbles in the front pressure chamber to an oil tank in the pump body.

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