JP6581009B2 - Forward / reverse switching hand pump for vibration compaction machine - Google Patents

Description

  The present invention relates to a hand pump for a vibration compactor used for compacting work such as ground, and in particular, by changing the rotation phase of one eccentric pendulum of a pair of eccentric pendulums in a vibration generator, The present invention relates to a forward / reverse switching hand pump used in a vibration compactor configured to move a machine body forward and backward by a composite vector.

  Conventionally, among the pair of eccentric pendulums in the vibration generator, the rotation phase of one eccentric pendulum (the phase with respect to the other eccentric pendulum) is changed, and the aircraft can be moved forward or backward by the resultant vector ( There is known a vibration compactor configured so that it can switch back and forth. This type of vibration compaction machine is configured to generate hydraulic power by rotating a forward / reverse lever attached to the operation handle and to freely change the phase of the eccentric pendulum by this hydraulic power. There are many.

  More specifically, the hydraulic cylinder (with a driven piston) that operates the forward / reverse switching shaft (the shaft that changes the phase of one eccentric pendulum) of the vibration generator, and the forward / reverse switching provided on the operation handle of the fuselage. A hydraulic cylinder (with a built-in drive piston) of a hand pump (hereinafter simply referred to as “hand pump”) is connected by a hydraulic hose, and the drive piston of the hand pump and the driven piston of the vibration exciter are connected with hydraulic pressure. When the forward / reverse lever attached to the hand pump is operated to rotate (forward to backward tilt), the hand piston drive piston is operated and the driven piston of the vibration generator (and A forward / reverse switching shaft) is operated, whereby the phase of the eccentric pendulum is changed, and forward / backward switching and speed adjustment are performed.

  Among such vibration compacting machines, in a so-called lightweight class vibration compacting machine having a body weight of 200 kg or less, in consideration of the convenience of operation, the operator releases the hand from the forward / reverse lever. In particular, a mechanism is adopted in which the aircraft's traveling direction and speed are “full speed forward”. In other words, when the eccentric pendulum is rotating in the vibration generator, the driven piston of the vibration generator is always moved to the hand pump (drive piston) side by the reaction force (mechanical pushing back force) generated by the rotation of the eccentric pendulum. When the operator releases his / her hand from the forward / reverse lever, the hydraulic oil is pushed out from the vibration generator to the hand pump side by this mechanical pushing back force. If this state continues, the maximum amount of hydraulic oil finally flows into the hydraulic cylinder of the hand pump, the drive piston is pushed backward (the side opposite to the hydraulic hose), and the traveling direction and speed of the aircraft are “Full speed forward”.

  When the operator operates the forward / reverse lever from the state in which the forward / reverse lever is in the “full speed forward” position (the drive piston is pushed to the rearmost side in the hand pump), the hand pump is operated according to the amount of operation. The drive piston inside moves to the hydraulic hose side, the hydraulic oil is discharged from the hand pump, and the hydraulic oil flows into the hydraulic cylinder of the vibration generator, against the mechanical push-back force caused by the rotation of the eccentric pendulum. The driven piston is pushed rearward (opposite to the hydraulic hose), and the phase of the eccentric pendulum is changed. As a result, the traveling direction of the aircraft is switched and the speed is adjusted.

  In this type of vibration compactor, a check valve may be disposed in the drive piston of the hand pump. When the check valve is opened, the front side (hydraulic hose side) and the rear side (oil tank side) of the drive piston in the hydraulic cylinder of the hand pump are in communication with each other, and the air mixed in the hydraulic oil is removed from the drive piston. It is used to escape to the oil tank formed on the rear side and to replenish hydraulic oil from the oil tank to the front side of the drive piston. When the operator releases his / her hand from the forward / reverse lever, the check valve spring The valve element is separated from the valve seat and opened by the repulsive force.

  When such a check valve is arranged in the drive piston, when the operator releases his / her hand from the forward / reverse lever, the check valve is opened, so that the drive piston acts from the vibration generator side. Release from the force (hydraulic pressure from the driven piston) prevents the forward / reverse lever from returning to the “full speed forward” position. For this reason, when a check valve is arranged in the drive piston, an operating force (mechanical push-back force from the vibration generator side) for returning the drive piston to the “full speed forward” position when the forward / reverse lever is not operated. ) Is often arranged on the front side (hydraulic hose side) of the drive piston to provide an urging force in the same direction as the mechanical pushing back force to the drive piston (Japanese Patent Laid-Open No. 2000-17607). No. publication).

JP 2000-17607 A JP 2002-317405 A JP 2002-339313 A JP 2005-179976 A JP 2005-200830 A

  However, the auxiliary spring having the urging force in the same direction as the mechanical push-back force moves the forward / reverse lever from the “full speed forward” position toward the “low speed forward”, “neutral”, or “reverse” side. This will increase the load for operation, resulting in an excessive burden on the operator.

  The present invention is intended to solve such a problem in the prior art, and can be configured with a small number of parts. Further, the operation force is reduced, the burden on the operator is reduced, and the operation is followed. It is an object of the present invention to provide a forward / reverse switching hand pump for a vibration compactor capable of improving performance.

  A forward / reverse switching hand pump for a vibration compaction machine according to the present invention is used by being connected to a vibration generator and a hydraulic hose mounted in the body of the vibration compaction machine. A drive piston inserted into the interior of the cylinder, and an oil tank formed on the rear side of the drive piston. The drive piston is disposed inside the outer cylinder portion and in contact with the inner peripheral surface of the cylinder. A cam with a forward / reverse lever connected and a roller pivotally attached to the tip is disposed on the rear side of the drive piston, and in the rear half of the drive piston insert, A link mechanism that holds the front and rear sides of the roller and holds them inside is formed, and a flow passage that connects the hydraulic hose side and the oil tank side of the cylinder in the drive piston, and opens and closes the flow passage Che The check valve is composed of an oil tank side valve element formed in the insertion part and a hydraulic hose side valve seat formed in the outer cylinder part, and the outer cylinder part and the insertion part. The valve body on the oil tank side is pressed against the valve seat on the hydraulic hose side by the check valve spring disposed between the two and the valve, and the check valve is always urged in the closing direction.

  As the check valve spring, it is preferable to use a check valve spring having a biasing force larger than the mechanical pushing back force acting from the side of the vibration generator, and a relief valve (oil oil) that opens and closes the flow passage in the drive piston. The valve body on the oil tank side is constituted by a tank side valve body and a hydraulic hose side valve seat, and the oil tank side valve body is hydraulic hose by a relief valve spring having a biasing force larger than the mechanical pushing back force acting from the vibration generator side. Preferably, the relief valve is always urged in the closing direction by being pressed against the side valve seat.

  The forward / reverse switching hand pump for the vibration compactor of the present invention is mechanically pushed back from the vibration generator side in order to return the drive piston to the “full speed forward” position when the forward / backward lever is not operated, as in the prior art. There is no need to install an auxiliary spring that gives the drive piston the same biasing force as the force, and it can be configured with a small number of parts, reducing the operating force and reducing the burden on the operator, and operation followability Can be improved. Moreover, it is possible to easily carry out air bleeding and hydraulic oil replenishment in the hydraulic circuit as required.

FIG. 1 is a cross-sectional view showing the internal structure of a hand pump 1 according to the present invention, and is a view showing a state in which the airframe is in “full speed forward”. FIG. 2 is a cross-sectional view showing the internal structure of the hand pump 1 according to the present invention and is a view showing a state where the traveling direction of the airframe is “neutral”. FIG. 3 is a cross-sectional view showing the internal structure of the hand pump 1 according to the present invention, and is a view showing a state in which the airframe is “full-speed reverse”. FIG. 4 is an enlarged cross-sectional view showing the internal structure of the hand pump 1 according to the present invention, and shows a state where the check valve 54 is closed. FIG. 5 is an enlarged cross-sectional view showing the internal structure of the hand pump 1 according to the present invention, and shows a state where the check valve 54 is opened. FIG. 6 is an enlarged cross-sectional view showing an internal structure in another configuration example of the hand pump according to the present invention. FIG. 7 is a diagram illustrating a state in which the link mechanism portion 52a and the roller 7 of the hand pump 1 illustrated in FIG. 2 are viewed from a lower viewpoint.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention “forward / reverse switching hand pump for vibration compaction machine” (hereinafter simply referred to as “hand pump”) will be described below with reference to the accompanying drawings. The hand pump according to the present invention is mounted on the upper part of an operation handle (not shown) protruding rearward of a vibration compacting machine (not shown) and mounted in the body of the vibration compacting machine. Via a hydraulic cylinder (not shown) on the device (not shown) side (following piston is inserted, the forward / reverse switching shaft is moved in the axial direction to change the phase of one eccentric pendulum) and a hydraulic hose (not shown) Connected and used.

  FIG. 1 is a sectional view showing an internal structure of a hand pump 1 according to the present invention. As shown in the figure, the hand pump 1 includes a casing 2 in which a cylinder 3 (hydraulic cylinder) and an oil tank 4 are formed.

  In front of the cylinder 3 (on the left side in FIG. 1), an opening 3 a that is connected to a hydraulic hose (not shown) and through which hydraulic oil enters and exits is formed. The cylinder 3 is reciprocated in the longitudinal direction of the cylinder 3. A drive piston 5 inserted as possible is arranged. The drive piston 5 includes an outer cylinder portion 51 that is in sliding contact with the inner peripheral surface of the cylinder 3, and an insertion portion 52 that is disposed inside the outer cylinder portion 51.

  In the casing 2 (in the oil tank 4), a cam 6 held so as to be rotatable around a horizontal central axis C is disposed, and at the tip of the cam 6, the cam 6 is rotated. A roller 7 for smoothly transmitting to the drive piston 5 is pivotally attached. In the oil tank 4, the rear half of the insertion portion 52 of the drive piston 5 protrudes, and the rear half of the insertion portion 52 is located on the front side of the roller 7 (left side in FIG. 1). ) And the rear side (right side in FIG. 1), and a link mechanism portion 52a for holding the roller 7 inside is formed.

  Note that a base end portion of a forward / reverse lever (not shown) is fixed to the cam 6, and when the operator rotates the forward / backward lever, the cam 6 rotates around the axis C, and the roller 7 at the distal end thereof. Swings within a predetermined range. More specifically, when the forward / reverse lever is tilted forward, the roller 7 moves backward (right side in FIG. 1), and when the forward / backward lever is tilted backward, the roller 7 moves forward (left side in FIG. 1). To do. Such a swinging motion of the roller 7 is converted into a reciprocating motion of the drive piston 5 in the cylinder 3 via the link mechanism 52 a that holds the roller 7 inside. Then, by the reciprocating operation of the drive piston 5, the hydraulic oil is discharged from the cylinder 3 to the hydraulic hose side, or flows into the cylinder 3 from the hydraulic hose side, and the driven piston and the forward / reverse switching shaft of the vibration generator are moved. By operating, the phase of the eccentric pendulum is changed, the direction of travel (forward / backward or neutral) of the vibration compactor is switched, and the speed is adjusted.

  Here, the operation | movement aspect of the hand pump 1 which concerns on this invention is demonstrated. FIG. 1 shows a state in which the outer cylinder portion 51 of the drive piston 5 is located on the most rear side (oil tank 4 side) in the cylinder 3, and in this state, the front side of the drive piston 5 ( The space S (volume) in the cylinder 3 on the hydraulic hose side is almost maximized. In this case, the amount of hydraulic oil flowing into the cylinder 3 from the hydraulic hose side is maximized, and the body of the vibration compactor is “full speed forward”.

  From this state, the cam 6 is rotated by operating to the rear side of the forward / reverse lever (not shown) and the roller 7 is moved to the position shown in FIG. 2 (pushing it toward the cylinder 3 side). The drive piston 5 moves forward (on the opposite side to the oil tank 4, left side in FIG. 2) against the mechanical pushing back force (oil pressure from the driven piston) from the device side, and the space S in the cylinder 3 is increased. Half of the capacity hydraulic fluid flows out from the cylinder 3 to the hydraulic hose side, the driven piston of the vibration generator and the forward / reverse switching shaft operate, and the body of the vibration compactor is “neutral” Become.

  From this state, the forward / reverse lever is further operated to the rear side, the cam 6 is further rotated, and the roller 7 is moved to the position shown in FIG. 3 (pushing it out to the cylinder 3 side). The drive piston 5 moves further forward (opposite to the oil tank 4, left side in FIG. 3) against the mechanical pushing back force from the vibration device side, the space S in the cylinder 3 is minimized, and the inside of the cylinder 3 The amount of hydraulic oil flowing out from the hydraulic hose to the hydraulic hose is maximized, the driven piston of the vibration generator and the forward / reverse switching shaft operate, and the body of the vibration compactor becomes “full speed reverse”.

  From this state (or from any state other than the state shown in FIG. 1), when the hand is released from the forward / reverse lever to the non-operating state, the hydraulic hose is moved according to the mechanical push-back force from the vibration generator side. The hydraulic oil flows into the cylinder 3 of the hand pump 1 from the side, the piston 5 is pushed rearward (oil tank 4 side), and returns to the position shown in FIG. 1 (“full speed forward” position).

  As described above, many conventional vibration compaction machine hand pumps have a flow passage in the drive piston and a check valve (the hydraulic hose side and oil tank side of the drive piston in the cylinder communicate with each other and are mixed into the hydraulic oil. A flow passage for replenishing hydraulic oil from the oil tank to the front side of the drive piston and a valve for opening and closing the flow passage) are disposed. Is released by the check valve spring when the hand is released from the forward / reverse lever, and the drive piston is released from the mechanical pushing back force from the vibration generator side. The auxiliary spring to be urged is disposed in the cylinder. However, in the hand pump 1 according to the present invention, such an auxiliary spring is used. Ku, the drive piston at the time of non-operation of the forward-reverse lever 5 (and the forward-reverse lever) can be returned to the "full speed forward" position.

  This point will be specifically described. Also in the hand pump 1 according to the present invention, as shown in FIG. 4, the hydraulic hose side (opening 3 a side) and the oil tank 4 side communicate with each other in the drive piston 5. The flow passage 53 and a check valve 54 that opens and closes the flow passage 53 (a conical valve body 54a disposed on the oil tank 4 side and a circular stepped valve seat 54b disposed on the hydraulic hose side) Configured) is formed. However, unlike the conventional one, the check valve 54 is closed from the oil tank 4 side toward the hydraulic hose side by the check valve spring 55 disposed between the outer cylinder portion 51 and the insertion portion 52. The valve body 54a on the oil tank 4 side is always urged in the direction in which the valve body 54a is pressed toward the valve seat 54b on the hydraulic hose side.

  Since the check valve spring 55 has an urging force larger than the mechanical pushing back force from the vibration generator side, the check valve spring 55 is in the state shown in FIGS. 3 and 4 (or any state other than the state shown in FIG. 1). In this state, when the operator releases his / her hand from the forward / reverse lever, even if hydraulic oil flows into the cylinder 3 from the hydraulic hose side according to the mechanical pushing back force from the vibration generator side, The check valve 54 is not pushed open by the oil (the flow passage 53 is not in a communicating state), and as a result, the piston 5 is pushed out to the oil tank 4 side, and the “full speed forward” position (see FIG. 1). Return to.

  When the air mixed in the hydraulic oil escapes from the cylinder 3 to the oil tank 4 (air release in the hydraulic circuit) or when the hydraulic oil is to be replenished from the oil tank 4 to the front side of the drive piston 5. Is a state in which the outer cylinder portion 51 of the drive piston 5 is in the most rear side in the cylinder 3 (a position where it abuts against a stopper 3b formed at the end of the oil tank 4 side in the cylinder 3 as shown in FIG. 5). That is, from the state of the “full speed forward” position, the forward / reverse lever is further tilted forward to move the roller 7 slightly backward.

  Then, the insertion portion 52 is slightly retracted against the urging force of the check valve spring 55, and as shown in FIG. 5, the valve body 54a is separated from the valve seat 54b, the check valve 54 is opened, and the drive piston 5 The hydraulic hose side and the oil tank 4 side are in communication with each other through the flow passage 53. As a result, air mixed in the hydraulic oil is released from the cylinder 3 to the oil tank 4, or from the oil tank 4 to the drive piston 5 It becomes possible to replenish hydraulic oil to the front side of the.

  In addition, when the forward / reverse lever is suddenly operated from the reverse side to the forward side, negative pressure is generated in the hydraulic circuit (between the driving piston 5 of the hand pump 1 and the driven piston of the vibration generator). When the negative pressure in the hydraulic circuit is larger than the urging force of the check valve spring 55, it is released (communicated with the oil tank 4 side), and can be generated in the airframe by such a rapid switching operation. Can reduce the impact.

  Further, as shown in FIG. 6, the relief valve 56 (relief valve spring 57 presses the valve body on the oil tank 4 side toward the hydraulic hose side valve seat by the relief valve spring 57 in the flow passage 53 so that the valve is closed. When the pressure in the hydraulic circuit suddenly increases due to the rapid operation of the forward / reverse lever from the forward side to the reverse side, The part can be released to the oil tank 4 side, and the impact that can occur in the airframe by such a rapid switching operation can be reduced. In addition, it is preferable to use the relief valve spring 57 used here which has a biasing force larger than the mechanical push-back force acting from the side of the vibration generator.

  In the above-described embodiment, a conical shape is used as the valve body 54a of the check valve 54, but the check valve 54 may be a ball valve by using a ball-type valve body.

  Further, as shown in FIG. 7 (a view showing the link mechanism portion 52a and the roller 7 of the hand pump 1 shown in FIG. 2 as viewed from the lower side in FIG. 2), the link mechanism portion 52a It is preferable not only to hold the front side and the rear side, but also to have a frame shape surrounding both the left and right sides, and to be configured so that the roller 7 is inserted inside the frame. In this case, the strength and durability of the link mechanism 52a can be improved.

  Furthermore, as shown in FIG. 7, the roller 7 is preferably pivotally attached to the tip of the cam 6 via a bearing 8 (ball bearing or needle bearing). In this case, the wear resistance at the connection portion between the roller 7 and the cam 6 can be improved, and the swinging motion of the cam 6 can be more smoothly converted into the reciprocating motion of the drive piston 5 so The operability of the lever can be improved.

1: Hand pump,
2: casing,
3: Cylinder
3a: opening,
3b: stopper,
4: Oil tank,
5: Drive piston,
6: Cam,
7: Laura,
8: Bearing,
51: outer cylinder part,
52: interpolation part,
52a: Link mechanism part,
53: Flow path,
54: Check valve,
54a: valve body,
54b: valve seat,
55: Check valve spring,
56: relief valve,
57: Relief valve spring

Claims (7)

A forward / reverse switching hand pump for a vibration compactor used by being connected to a vibration generator and a hydraulic hose mounted in the body of the vibration compactor,
A cylinder, a drive piston inserted into the cylinder, and an oil tank formed on the rear side of the drive piston;
The drive piston is constituted by an outer cylinder portion that is in sliding contact with the inner peripheral surface of the cylinder, and an insertion portion that is disposed inside the outer cylinder portion,
On the rear side of the drive piston, a cam with a forward / reverse lever connected and a roller pivoted at the tip is arranged,
In the latter half of the internal part of the drive piston, there is formed a link mechanism that holds the front and rear sides of the roller and holds them inside.
In the drive piston, a flow passage that connects the hydraulic hose side and the oil tank side of the cylinder and a check valve that opens and closes the flow passage are formed.
The check valve is composed of an oil tank side valve element formed in the insertion part and a hydraulic hose side valve seat formed in the outer cylinder part, and is arranged between the outer cylinder part and the insertion part. The valve body on the oil tank side is pressed against the valve seat on the hydraulic hose side by the check valve spring, and the check valve is constantly urged in the closing direction ,
As a check valve spring, reverse switching hand pump before vibrating compactor characterized in that there use those having a large biasing force than the mechanical push-back force acting from the exciter device. A relief valve for opening and closing the flow passage is disposed in the drive piston,
The relief valve is composed of a valve body on the oil tank side and a valve seat on the hydraulic hose side, and the relief valve spring presses the valve body on the oil tank side against the valve seat on the hydraulic hose side to close the relief valve. 2. The forward / reverse switching hand pump for a vibration compactor according to claim 1, wherein the forward / reverse switching hand pump is constantly biased in the direction. 3. The forward / reverse switching hand pump for a vibration compactor according to claim 2 , wherein a relief valve spring having a biasing force larger than a mechanical pushing back force acting from the vibration generator side is used. The forward / reverse switching hand pump for a vibration compactor according to any one of claims 1 to 3 , wherein the check valve is configured as a ball valve by using a ball-type valve body for the check valve. . The link mechanism is configured in a frame shape that not only holds the front and rear sides of the roller, but also surrounds both the left and right sides, and the roller is inserted inside the frame-shaped link mechanism. The forward / reverse switching hand pump for a vibration compactor according to any one of claims 1 to 4 . The forward / reverse switching hand pump for a vibration compactor according to any one of claims 1 to 5 , wherein a roller is pivotally attached to the tip of the cam via a ball bearing or a needle bearing. The forward / reverse switching hand pump for a vibration compactor according to any one of claims 1 to 6 , wherein the check valve is disposed in the vicinity of the substantial center in the drive piston.

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