JP2515670B2 - Hydraulic pump for switching forward / backward of vibration compactor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pump used for switching an oscillating shaft in a vibration compactor in forward and backward directions, and more particularly, an oscillating body forward and backward switching shaft in an oscillating body case. The present invention relates to a forward / backward switching hydraulic pump in a vibration compactor of the type using a hydraulic pump as a means for switching the forward / backward direction.

[0002]

2. Description of the Related Art Generally, in order to move a vibration compactor forward and backward, the phase of an eccentric pendulum as a vibrating body is changed over by 180 °, and the phase of the eccentric pendulum is changed. As a means for changing the rotation angle of the pendulum shaft by 180 °, the rotation angle of the pendulum shaft is changed by a mechanism for engaging and disengaging a pawl operated from the outside (for example, Japanese Utility Model Publication No. 58-17768, Japanese Utility Model Publication No. 61- 1255
No. 11) and the transmission gear provided on the pendulum shaft are switched by the operation of hydraulic pressure supplied from the outside (for example, Japanese Patent Publication No. 61-48997, JP-A 1-26010).
No. 7) is known.

Among the above-mentioned forward / reverse switching means, the type in which the rotation angle of the pendulum shaft is switched by hydraulic operation allows forward / backward movement of the machine body by increasing / decreasing the supply amount of pressure oil or switching the supply direction of pressure oil. Since it can be obtained, it has an advantage that switching between forward and backward can be performed smoothly without impact, as compared with the case of using the claw disengagement mechanism.

Among the above-mentioned hydraulic pressure switching methods, the mechanism of Japanese Patent Publication No. 61-48997 is the forward movement of the body when the pressure oil is supplied to the maximum by the lever and when it is supplied to the minimum. Since the neutral state is in the middle, the operator must always hold the lever of the pressure oil supply device at the intermediate position, or the operator will not be able to obtain the neutral state of the machine, which makes the operation troublesome. There is a problem that is.

On the other hand, in the mechanism of Japanese Patent Laid-Open No. 1-260107, the direction of pressure oil supply is controlled by operating a lever with respect to one end side or the other end side of a piston rod in a rotary shaft equipped with a transmission gear. Therefore, if the lever is left in a neutral state, the forward and backward movements of the machine body will not be performed, and there is an advantage that safety during operation can be secured.

[0006]

On the other hand, Japanese Patent Application Laid-Open No. 1-26
In the mechanism of No. 0107, the pressure oil is supplied from the pressure oil supply device outside the machine to the one end side or the other end side of the piston rod in the rotary shaft on which the transmission gear in the vibrating body is mounted, and the forward and backward movement is performed. In order to perform switching, the forward pressure oil chamber and the reverse pressure oil chamber provided at both ends of the piston rod in the pressure oil supply device, and one end side and the other end side of the piston rod in the vibrating body are respectively They are connected by a forward pressure oil supply circuit and a reverse pressure oil supply circuit.

Therefore, the forward pressure oil supply circuit and the reverse pressure oil supply circuit that connect the pressure oil supply device and the vibrator are filled with the same amount of pressure oil, and the forward pressure oil supply device is used. When a predetermined amount of pressure oil is sent from the pressure oil chamber to one end side of the vibration oscillating body, a predetermined amount of pressure oil at the other end side of the vibration oscillating body returns to the reverse movement pressure oil chamber of the pressure oil supply device, and vice versa. When a predetermined amount of pressure oil is sent from the reverse pressure oil chamber of the pressure oil supply device to the other end side in the vibrating body,
A predetermined amount of pressure oil on the one end side in the vibrating body returns to the forward pressure oil chamber of the pressure oil supply device.

As described above, theoretically, if the forward pressure oil supply circuit and the reverse pressure oil supply circuit connecting the pressure oil supply device and the vibrator are filled with the same amount of pressure oil, respectively. By sending a predetermined pressure oil discharge amount from each pressure oil supply circuit, switching between forward and reverse is appropriately performed. However, in reality, some air is mixed as bubbles in the pressure oil filled in the forward pressure oil supply circuit and the reverse pressure oil supply circuit, respectively, or initially in each circuit. Even if the same amount of pressure oil is filled, the pressure oil may leak due to repeated vibrations during use, resulting in pressure oil leaking from the seal portion or the joint portion in the circuit, and the pressure oil may be reduced.

As described above, when some air is mixed as bubbles in the pressure oil in the circuit or the pressure oil in the circuit is depleted due to leakage, the pressure in each circuit is thereby reduced. The oil is under pressure or becomes unbalanced,
Even if the lever of the pressure oil supply device is turned toward the forward side or the backward side to the predetermined angle position during use, the amount of pressure oil required to switch between forward and reverse cannot be obtained at the predetermined lever rotation position. However, there arises a problem that it becomes difficult to perform the switching operation properly and smoothly.

[0010]

[Means for Solving the Problems] As a measure for solving such a problem, a switching operation of an oscillating body which is sent to each pressure oil supply device in advance through respective circuits for forward and backward movement is performed. The amount of pressure oil that is substantially larger than the required discharge amount of pressure oil is stored, and when the lever is turned to a predetermined angle position toward the forward side or the reverse side, switching operation of the vibration generator is performed. When the switching operation is completed by rotating the lever to a predetermined angular position so that a quantity of pressure oil that is slightly larger than the discharge amount of pressure oil required for is sent through each circuit, A means is conceivable in which the excess pressure oil other than the amount required for this switching operation flows into another flow path direction in the pressure oil supply device.

The present invention provides a hydraulic pump for switching between forward and backward movements of a vibration compactor capable of solving the above-mentioned problems. As a concrete means therefor, the invention described in claim 1 is provided. The forward-reverse switching hydraulic pump includes a piston rod that moves in a pump case by the rotation of a lever, and a forward pressure oil chamber and a reverse pressure oil chamber that communicate with a cylinder of the vibration generator case at both ends of the piston rod. A preliminary pressure oil chamber connected to one of the pressure oil chambers,
The piston rod has a valve for releasing a part of the pressure oil into the other pressure oil chamber when the piston rod is pressurized in one pressure oil chamber direction, and the preliminary pressure oil chamber has
There is a valve that allows a part of the pressure oil to escape into the preliminary pressure oil chamber when the piston rod is pressurized in the direction of the pressure oil chamber connected to the preliminary pressure oil chamber. A pressure oil supply channel is provided between the pressure oil chamber and the pressure oil chamber.

Further, in the forward-reverse switching hydraulic pump according to the second aspect of the present invention, a pressure communicating between the forward pressure oil chamber and the reverse pressure oil chamber is communicated with the inside of the piston rod along the axial direction. An oil passage is provided, and a check ball valve that opens from the forward pressure oil chamber toward the reverse pressure oil chamber is arranged in the pressure oil passage.

According to another aspect of the present invention, there is provided a hydraulic pump for switching between forward and reverse movements, wherein a pressure oil flow passage coaxial with a pressure oil flow passage of the piston rod is provided in the preliminary pressure oil chamber, and the pressure oil flow passage. A valve body having a check ball valve that opens from the reverse pressure oil chamber toward the preliminary pressure oil chamber is provided therein.

Further, in the forward-reverse switching hydraulic pump according to the invention described in claim 4, in the gear case for operating the piston rod in the pump case, from the preliminary pressure oil chamber to the forward pressure oil chamber. Further, a replenishing flow path for supplying pressure oil to the reverse pressure oil chamber is provided.

[0015]

In the hydraulic pump for switching between forward and reverse movements according to the first aspect of the present invention, the lever provided on the pump case is rotated to move the piston rod disposed inside the case, for example, for advancing below the case. When moving toward the pressure oil chamber, the pressure oil in the advance pressure oil chamber is discharged into the advance cylinder of the vibrating body. Since a larger amount of pressure oil than the discharge amount of the pressure oil necessary for the switching operation of the vibrator is stored in the forward pressure oil chamber, the pressure oil is stored in the forward cylinder of the vibrator. When it is sent and a predetermined switching operation is performed, excess pressure oil than the pressure oil discharge amount required for the switching operation pushes open the valve provided on the piston rod to move to the forward pressure oil chamber. It flows into the reverse pressure oil chamber on the opposite side.

Further, when the piston rod is moved in the direction of the reverse pressure oil chamber above the case opposite to the above by the rotation of the lever, the pressure oil in the reverse pressure oil chamber is stored in the reverse cylinder of the vibrator. However, similarly to the above, since a larger amount of pressure oil than the discharge amount of pressure oil necessary for the switching operation of the vibrator is stored in the reverse pressure oil chamber, the pressure oil is When the vibrating body is sent into the reverse cylinder and a predetermined switching operation is performed, excess pressure oil beyond the pressure oil discharge amount required for the switching operation is reserved in the reverse pressure oil chamber. The valve provided in the pressure oil chamber is pushed open to flow into the preliminary pressure oil chamber.

On the other hand, since a pressure oil supply passage is provided between the preliminary pressure oil chamber and the forward pressure oil chamber and the reverse pressure oil chamber, as described above, the forward pressure oil chamber is provided. From the reverse pressure oil chamber to the backup pressure oil chamber, the pressure oil flowing from the reverse pressure oil chamber into the backup pressure oil chamber again through the replenishment flow path to the forward pressure oil chamber and The pressure oil discharge amount necessary for the switching operation and a larger amount of pressure oil are supplied from the forward pressure oil chamber and the reverse pressure oil chamber to the vibrating body. To be done.

According to the second aspect of the present invention, there is provided a hydraulic pump for switching between forward and backward movement, wherein a pressure communicating from the forward pressure oil chamber to the reverse pressure oil chamber is communicated with the inside of the piston rod along the axial direction. An oil flow path is provided, and a check ball valve that opens from the forward pressure oil chamber toward the reverse pressure oil chamber is arranged in the pressure oil flow path. After the pressure oil is discharged and the vibrating body reliably performs the switching operation in the forward direction, the excess pressure oil of the pressure oil discharge amount required for this switching operation is the pressure oil flow in the piston rod. The non-return ball valve is pushed open from the road, and is smoothly discharged into the reverse pressure oil chamber on the opposite side.

According to the third aspect of the present invention, there is provided a hydraulic pump for switching between forward and reverse movements, wherein a pressure oil flow passage coaxial with the pressure oil flow passage of the piston rod is provided in the preliminary pressure oil chamber, and the pressure oil flow is provided. Since a valve body having a check ball valve that opens in the direction of the preliminary pressure oil chamber from the reverse pressure oil chamber is provided in the passage, the pressure oil in the reverse pressure oil chamber is discharged by the piston rod, After the vibrating body has surely performed the switching operation in the reverse direction, the excess pressure oil of the pressure oil discharge amount required for this switching operation is reversed from the pressure oil passage in the valve body in the preliminary pressure oil chamber. Push the stop ball valve open,
The oil is smoothly discharged into the preliminary pressure oil chamber.

According to another aspect of the present invention, there is provided a hydraulic pump for switching between forward and reverse movements, wherein the forward pressure oil chamber is moved from the preliminary pressure oil chamber into a gear case for operating the piston rod in the pump case. Since a replenishment flow path for supplying pressure oil to the reverse pressure oil chamber is provided,
The pressure oil stored in the preliminary pressure oil chamber can be returned to the forward pressure oil chamber and the reverse pressure oil chamber again through the replenishing flow path in the gear case, and the forward pressure oil chamber can be returned. Excess pressure oil that has flowed out into the room and excess pressure oil that has flowed into the backup pressure oil chamber from the reverse pressure oil chamber are constantly replenished in the respective pressure oil chambers, and the forward pressure oil chamber and the reverse pressure oil chamber It is possible to supply the pressure oil discharge amount required for the switching operation and the pressure oil in an amount larger than the discharge amount toward the vibrating body.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a pump case 10 constituting this hydraulic pump includes a cylinder case 12 in which a piston rod 11 is incorporated and the piston rod 11. It comprises a gear case 13 to which a lever 19 for operation is attached, and a cylinder case 12 and a preliminary pressure oil chamber 14 provided at one end of the gear case 13.

The piston rod 11 is the rack gear 1.
6 engages with a pinion gear 15 provided in the gear case 13 and rotates the lever 19 to move in the cylinder case 12. Further, a forward pressure oil chamber 17 and a reverse pressure oil chamber 18 are provided at both ends of the cylinder case 12, and an opening 17 a of the forward pressure oil chamber 17 and an opening of the reverse pressure oil chamber 18 are provided. As shown in FIG. 2, the portion 18a is provided with a vibrating body forward / backward switching shaft 21 in the vibrating body 20 of the vibration compactor.
Are connected to cylinders 22 and 23, both ends of which are axially mounted, via pressure oil supply circuits 24 and 25, respectively.

Further, the piston rod 11 is provided inside the axial direction from the forward pressure oil chamber 17 to the reverse pressure oil chamber 1.
A pressure oil flow passage 26 communicating with each other in eight directions is provided. Inside the pressure oil flow passage 26, a forward movement pressure oil chamber 17 is provided by a spring 28.
A non-return ball valve 27 is arranged which is pressed to the side and is opened by pressure oil pressurized from the forward pressure oil chamber 17 toward the reverse pressure oil chamber 18.

A cylindrical valve body 29 is mounted in the preliminary pressure oil chamber 14 at a position communicating with the reverse pressure oil chamber 18 of the cylinder case 12, and the piston rod is attached to the valve body 29. 11 is provided with a pressure oil passage 30 coaxial with the pressure oil passage 26, and a spring 31 presses the pressure oil passage 30 inside the pressure oil passage 30 toward the reverse movement pressure oil chamber 18 side. A check ball valve 32, which is opened by pressure oil pressurized from 18 toward the preliminary pressure oil chamber 14, is arranged. It should be noted that an opening portion 34 to which a removable screw plug 33 is attached is provided at the upper end of the preliminary pressure oil chamber 14, and when the pressure oil 40 in the inside is insufficient due to leakage or the like, a necessary amount of the insufficient shortage is provided. Pressure oil can be supplied from the outside.

Further, an orifice 35 is opened on the side of the pressure oil passage 30 in the valve body 29 on the side of the spring 31 so that the pressure flowing into the pressure oil passage 30 from the reverse pressure oil chamber 18 side. When the oil opens the check ball valve 32, the pressure oil flowing into the pressure oil flow passage 30 flows into the preliminary pressure oil chamber 14 through the orifice 35.

In the gear case 13, pressure oil supply passages 36 and 37, one end of which communicates with the preliminary pressure oil chamber 14, are provided at positions including both sides of the pinion gear 15, and one of them is supplied. The flow path 36 is the cylinder case 1
Orifice 38 opened in the reverse pressure oil chamber 18 in FIG.
And the other replenishment flow path 37 communicates with the forward pressure oil chamber 1
7 communicates with an orifice 39 having a hole.

Further, in this hydraulic pump, the cylinder case 1 including the inside of the forward pressure oil chamber 17 and the backward pressure oil chamber 18
2, the inside of the preliminary pressure oil chamber 14, and the pinion gear 15
The pressure oil 40 is filled into the outer periphery of the gear case 13 and the entire area of the gear case 13 including the supply channels 36 and 37.

Therefore, for example, as shown in FIG. 2, the lever 19 is rotated to move the piston rod 11 in the direction of the forward pressure oil chamber 17, and the pressure oil in the forward pressure oil chamber 17 is compressed. When the oil is fed to the forward cylinder 22 of the vibration generator 20 of the vibration compactor via the oil supply circuit 24, the forward pressure oil chamber 1
Even if a small amount of air bubbles are mixed in the pressure oil inside 7, it is possible to discharge sufficient pressure oil necessary to switch the vibrating body 20 to the forward side. In that case, the excess pressure oil other than the discharge amount required to switch the vibrating body 20 to the forward side is
The check ball valve 27 in the pressure oil passage 26 of the piston rod 11 is pushed open to flow into the reverse pressure oil chamber 18.

Similarly, when the lever 19 is rotated to the opposite side to move the piston rod 11 toward the reverse pressure oil chamber 18, the pressure oil in the reverse pressure oil chamber 18 Even if a small amount of air bubbles are mixed in, it is possible to discharge sufficient pressure oil necessary for switching the vibrating body 20 to the reverse side, and in that case, to switch the vibrating body 20 to the reverse side. Excess pressure oil other than the required discharge amount pushes open the check ball valve 32 of the pressure oil passage 30 in the valve body 29 of the preliminary pressure oil chamber 14 and flows into the preliminary pressure oil chamber 14.

As described above, a part of the pressure oil in the forward pressure oil chamber 17 flows out into the reverse pressure oil chamber 18, and a part of the pressure oil in the reverse pressure oil chamber 18 is a preliminary pressure oil. When it flows out into the chamber 14, the pressure oil in each pressure oil chamber becomes insufficient, but the preliminary pressure oil chamber 14, the forward pressure oil chamber 17, and the reverse pressure oil chamber 1
8 is connected to each other via the replenishment flow passages 36 and 37 of the gear case 13, so that the pressure oil in the preliminary pressure oil chamber 14 passes through the replenishment flow passages 36 and 37 and the forward movement pressure oil chamber 17 and the reverse movement. The pressure oil in the forward pressure oil chamber 17 and the reverse pressure oil chamber 18 is returned to the vibrating body 2 at all times.
The discharge amount can be made larger than the discharge amount required to switch 0 to forward and backward.

[0031]

As described above, according to the present invention,
Since it is possible to send a larger amount of pressure oil from the forward pressure oil chamber and the reverse pressure oil chamber than the discharge amount required to switch the vibrator to forward and backward movement, even if bubbles are mixed in the pressure oil. Even if the amount of pressure oil has decreased due to oil leakage,
A stable and reliable switching operation is always guaranteed.

Further, in the present invention, there is a preliminary pressure oil chamber in addition to the forward pressure oil chamber and the reverse pressure oil chamber. If the preliminary pressure oil chamber is used so as to be located at the upper end, the preliminary pressure oil chamber can be used. The mixed air bubbles in the pressure oil stored in are always located at the upper end of the pressure oil chamber, so that the bubbles may flow toward the forward pressure oil chamber and the reverse pressure oil chamber through the replenishment flow path. It is possible to prevent the problem of the device of this kind due to the inclusion of air bubbles in the pressure oil.

In the above construction, the lower side of the cylinder case has been described as the forward pressure oil chamber and the upper side has been described as the reverse pressure oil chamber. However, the lower side of the cylinder case is the reverse pressure oil chamber and the upper side thereof. It goes without saying that there is no problem even if it is used as a forward pressure oil chamber.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a forward / reverse switching hydraulic pump according to an embodiment of the present invention.

FIG. 2 is a mechanism explanatory view showing a configuration of a hydraulic pump of the present invention and a vibrating body of a vibration compactor.

FIG. 3 is a side view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 10: Pump Case 11: Piston Rod 12: Cylinder Case 13: Gear Case 14: Preliminary Pressure Oil Chamber 15: Pinion Gear 17: Forward Pressure Oil Chamber 18: Backward Pressure Oil Chamber 19: Lever 20: Vibrator 21: Shaking body forward / reverse switching shaft 24, 25: Pressure oil supply circuit 26: Piston rod internal pressure oil flow path 27, 32: Check ball valve 29: Valve body 30: Valve body internal pressure oil flow path 35, 38, 39: Orifice 36, 37: Supply channel 40: Pressure oil

Claims (4)

(57) [Claims] 1. A hydraulic pressure for axially moving an exciter forward / reverse switching shaft in an exciter case of a vibration compactor by an external hydraulic pump to switch rotation of the exciter in forward / backward directions. A pump, a piston rod that moves in the pump case by the rotation of a lever, and a forward pressure oil chamber and a reverse pressure oil chamber that communicate with the cylinder of the vibration generator case at both ends of the piston rod. A preliminary pressure oil chamber connected to one pressure oil chamber is provided, and when the piston rod is pressurized in one pressure oil chamber direction, a part of the pressure oil is introduced into the other pressure oil chamber. In addition to having a relief valve, a valve is provided in the preliminary pressure oil chamber to allow a part of the pressure oil to escape into the preliminary pressure oil chamber when the piston rod is pressurized in the direction of the pressure oil chamber connected to the preliminary pressure oil chamber. Having the preliminary pressure oil chamber and the forward movement A hydraulic pump for switching between forward and reverse movements of a vibration compactor, which has a pressure oil replenishing flow path between the pressure oil chamber for reverse and the pressure oil chamber for reverse. 2. A pressure oil flow passage communicating from the forward pressure oil chamber toward the reverse pressure oil chamber is provided inside the piston rod in the axial direction, and the forward movement is made in the pressure oil flow passage. The hydraulic pump for switching between forward and backward of the vibration compactor according to claim 1, further comprising a check ball valve that opens from the pressure oil chamber toward the reverse pressure oil chamber. 3. A pressure oil passage in the auxiliary pressure oil chamber, which is coaxial with the pressure oil passage of the piston rod, and opens in the pressure oil passage from the reverse pressure oil chamber toward the auxiliary pressure oil chamber. The hydraulic pump for switching between forward and backward movements of a vibration compactor according to claim 1, further comprising a valve body having a check ball valve. 4. A supply passage for supplying pressure oil from the preliminary pressure oil chamber to the forward pressure oil chamber and the reverse pressure oil chamber in a gear case for operating the piston rod in a pump case. The hydraulic pump for switching between forward and backward of the vibration compactor according to claim 1, wherein the hydraulic pump is provided.