JPH08159011A - Pistion pump motor - Google Patents

Abstract

PURPOSE: To suppress generation of noise and erosion accompanying with reverse flow toward a cylinder and a sucition port which are caused passing the notch groove of a valve plate. CONSTITUTION: Notch grooves 12, 12 for alleviatiny fluctuation in closing pressure of a cylinder are formed respectively on starting ends of a suction port 10 and a discharging port 11 in the contact surface of the cylinder block of a valve plate 6. A baffle plate 14 is provided so as to partition the starting side of the inside of a port as a damper chamber 30, and also a throttle passage 15 is provided so as to communicate the damper chamber 30 with the inlet side and the outlet side of a port block.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to improvements in piston pump motors.

[0002]

2. Description of the Related Art FIG. 1 shows a piston pump / motor.
2, the one configured as shown in Fig. 13 is known (Shokai Sho 6
3-96372). A cylinder block 2 is connected to the outer circumference of the pump shaft 20 and includes a plurality of cylinders 3 concentrically with the pump shaft 20. A piston 4 which is slidable in the axial direction is housed in each cylinder 3, and a shoe 21 is attached to the piston head. The shoe 21 is a pressing plate that contacts the swash plate 5, and the rotation of the cylinder block 2 causes the piston 4 to stroke in the axial direction. The valve plate 6 is fixed to the port block 7 of the casing 1, and the cylinder block 2 is pressed against the plate surface by a spring. The valve plate 6 controls suction and discharge of the cylinder 3, and a suction port 10 and a discharge port 11 are formed on a concentric circle with a predetermined space.

When the cylinder block 2 rotates integrally with the pump shaft 20, the piston 4 strokes by the swash plate 5, and in the process of exiting from the cylinder block 2, fluid is introduced from the inlet 9 side of the port block 7 into the suction port 10 of the valve plate 6. Through the discharge port 11 of the valve plate 6 to the outlet 8 side of the port block 7 in the process of entering the cylinder block 2.
Since the suction port 10 and the discharge port 11 of are separated,
Cylinder 3 centered on the bottom dead center and top dead center of piston displacement
However, a confinement phenomenon occurs in which none of these ports 10 and 11 communicates. Since the piston 4 also strokes during that time, when the cylinder 3 is compressed and expanded in a sealed state, abnormally high pressure or negative pressure is generated, which causes cavitation, vibration, and noise, and is generally used as a means for preventing this. V-shaped notches 12 and 13 are provided at the respective starting ends of the suction port 10 and the discharge port 11 so as to alleviate pressure fluctuations due to the closing of the cylinder 3.

[0004]

However, the piston 4
During the transition from the expansion stroke to the compression stroke of the cylinder 3, the cylinder 3 cuts off the communication with the suction port 10, and the cutout groove 1 of the discharge port 11
3, the high pressure fluid from the discharge port 11 flows back to the cylinder 3 through the notch groove 13, and the cylinder 3 disconnects from the discharge port 11 when the piston 4 shifts from the compression stroke to the expansion stroke, and the suction port 10 When communicating with the cutout groove 12 of No. 2, the high pressure fluid flows backward from the cylinder 3 through the cutout groove 12 to the suction port 10, so that high pressure and low pressure momentarily collide with each other at the suction port 11 and the cylinder 3, and new noise and erosion are generated. There was a problem of causing it.

An object of the present invention is to provide an effective solution to such problems.

[0006]

According to a first aspect of the present invention, a valve plate having a suction port and a discharge port on a concentric circle, a cylinder block rotating while contacting the valve plate, and a suction block depending on a rotation angle of the cylinder block. It is equipped with a cylinder that communicates with the port and the discharge port, and a piston that expands and contracts the volume of the cylinder by the reciprocating motion that accompanies the rotation of the cylinder block.In the expansion stroke of the piston, fluid is supplied to the cylinder from the inlet side of the port block through the suction port of the valve plate. In a piston pump / motor that sucks and discharges fluid from the cylinder through the discharge port of the valve plate to the outlet side of the port block during the compression stroke of the piston, from the start end of the suction port to the contact surface of the valve plate with the cylinder block A notch groove is formed to reduce the fluctuation of the closing pressure of the cylinder toward the end of the A baffle plate partitioning the start end parts in the damper chamber, a throttle passage for communicating the damper chamber to the inlet side of the port block provided.

According to the second aspect of the present invention, a valve plate having a suction port and a discharge port on a concentric circle, a cylinder block that rotates while contacting the valve plate, and a communication port that communicates with the suction port and the discharge port according to the rotation angle of the cylinder block. Cylinder to
Equipped with a piston that expands and contracts the volume of the cylinder by reciprocating movement due to the rotation of the cylinder block, sucks fluid from the inlet side of the port block through the suction port of the valve plate into the cylinder in the expansion stroke of the piston, and from the cylinder in the compression stroke of the piston In a piston pump / motor that discharges fluid to the outlet side of the port block through the discharge port of the plate, the closing pressure of the cylinder from the beginning of the discharge port to the end of the suction port on the contact surface of the valve plate with the cylinder block. Is provided with a baffle plate that divides the start end side inside the port into a damper chamber and a throttle passage that connects the damper chamber to the outlet side of the port block.

According to a third aspect of the present invention, in the first or second aspect of the invention, the valve wall is formed with a bottom wall that closes the port block side of the damper chamber.

[0009]

According to the first aspect of the present invention, when the cylinder is disconnected from the discharge port and communicates with the notch groove of the suction port at the time of the shift of the piston from the compression stroke to the expansion stroke, the high pressure fluid is sucked from the cylinder through the notch groove. Although it flows back to the port, this flow increases the pressure in the damper chamber and acts as the back pressure in the notch groove in the valve plate, so the high-pressure fluid from the cylinder gradually flows into the throttle passage, causing a reverse flow to the suction port. The instantaneous collision of high pressure and low pressure that accompanies it is mitigated, and the generation of erosion and noise can be reduced.

According to the second aspect of the present invention, when the cylinder is disconnected from the suction port and communicates with the notch groove of the discharge port during the transition from the expansion stroke of the piston to the compression stroke, the high pressure fluid from the discharge port passes through the notch groove. Although it flows back to the cylinder, the high-pressure fluid gradually flows from the throttle passage to the cylinder due to the cushioning action of the damper chamber, so the momentary collision of high pressure and low pressure due to the reverse flow to the cylinder is mitigated, and the generation of erosion and noise is reduced. it can.

According to the third aspect, since the damper chamber has the bottom wall, it is not necessary to close the bottom surface of the damper chamber with the wall surface of the port block. That is, it is not necessary to open the passage on the inlet side or the outlet side of the port block at a position biased from the damper chamber to the port end side of the baffle plate.

[0012]

1 and 2, reference numeral 6 denotes a valve plate which comes into contact with a cylinder block of a piston pump, in which a suction port 10 and a discharge port 11 are concentrically formed at a predetermined interval, and an expansion stroke of a piston 4 is formed. At the entrance 9 of port block 7
The fluid is introduced into the cylinder 3 from the side through the suction port 10, and the fluid is discharged from the cylinder 3 through the discharge port 11 to the outlet 8 side of the port block 7 in the compression stroke of the piston 4.

On the contact surface of the valve plate 6 with the cylinder block 2, a notch groove 12 having a V-shaped cross section extending from the starting ends of the suction port 10 and the discharge port 11 in the tangential direction of these ports,
13 is formed, and the damper chamber 30 is provided at the start end side inside each port.
A baffle plate 14 for partitioning is installed. These baffles 1
As shown in FIGS. 2 to 5, a through hole 15, notched recesses 16 and 17, or a plurality of slits 18 are formed in each of the throttle passages 4 as shown in FIGS. The slit 18 may be formed between the baffle plate 14 and the wall surface of the port block 7 as shown in FIG.

The inlet 9 side and the outlet 8 of the port block 7
Since the bottom of the damper chamber 30 is closed by the wall surface of the port block 7, the side passage is opened at a position biased from the damper chamber 30 to the port end side of the baffle plate 14. The baffle plate 14 can be fixed by inserting grooves into the suction port 10 and the discharge port 11 of the valve plate 6 as shown in FIG. 1, or by inserting the grooves, or by the ports 10 and 11 of the valve plate 6 as shown in FIG. It is possible to use either a method of bonding by welding or the like, or a method of forming a groove in the port block 7 as shown in FIG.

According to this structure, when the cylinder 3 cuts off the communication of the suction port 10 and communicates with the cutout groove 13 of the discharge port 11 when the piston 4 shifts from the expansion stroke to the compression stroke, high pressure fluid is discharged from the discharge port 13. Although it flows back to the cylinder 3 through the cutout groove 13, the throttle passage 15 of the baffle plate 14 restricts the high pressure from flowing into the damper chamber 30 from the outlet side of the port block 7, so that the cushioning action thereof causes high pressure fluid from the discharge port 11 to flow. Gradually flows toward the cylinder 3, so that the instantaneous collision of high pressure and low pressure due to the backflow to the cylinder 3 is mitigated, and the generation of erosion and noise can be reduced.

Further, when the cylinder 3 cuts off the communication of the discharge port 11 and communicates with the cutout groove 12 of the suction port 10 when the piston 4 shifts from the compression stroke to the expansion stroke, the high pressure fluid is sucked from the cylinder 3 through the cutout groove 12. Port 10
However, since a suitable back pressure is generated in the damper chamber 30 in the throttle passage 15, the high pressure fluid gradually flows from the cylinder 3 to the suction port 10 due to the cushioning action, and thus the high pressure due to the reverse flow to the suction port 10 is generated. The low-pressure momentary collision is mitigated, and the generation of erosion and noise can be reduced.

If the baffle plate 14 for partitioning the damper chamber 30 is made of a porous material, the porous baffle plate 14 can fulfill its function without intentionally processing the throttle passages 15-18. . The suction port 10 and the discharge port 11 of the valve plate 6 are not divided into the damper chamber 30 by the separate baffle plate 14 but the damper chamber 30 as shown in FIG.
The partition wall portion 14a corresponding to the baffle plate 14 may be integrally formed.

FIG. 7 shows another embodiment, in which a bottom wall 19 for closing the damper chamber 30 on the port block 7 side is formed in the valve plate 6. The same parts as those in FIG. 2 are designated by the same reference numerals. According to this, the bottom surface of the damper chamber 30 does not have to be closed by the wall surface of the port block 7, so that the passages on the inlet 9 side and the outlet 8 side of the port block 7 are biased from the damper chamber 30 to the port end side of the baffle plate 14. There is no need to change to. In addition, as shown in FIG.
It can also be formed on the bottom wall 19 of the.

The bottom wall 19 of the damper chamber 30 may be integrally formed with the valve plate 6 including the partition wall portion 14a corresponding to the baffle plate 14 for separating the ports 10 and 11, as shown in FIG. The passage 15 is the bottom wall 1 of the damper chamber 30 as shown in FIG.
9 can also be formed. Also, the throttle passages 15-18
Is not formed on the valve plate 6 side as shown in FIGS. 2 to 9, but is formed on the port block 7 side as shown in FIGS.
0 may be formed in a V-shaped or U-shaped notched concave portion 20 or a single slit or a plurality of slits 21 which communicate with the passages on the inlet 9 side and the outlet 8 side.

[0020]

According to the first aspect of the present invention, a valve plate having a suction port and a discharge port on a concentric circle, a cylinder block rotating while contacting the valve plate, and a suction port depending on the rotation angle of the cylinder block. It is equipped with a cylinder that communicates with the discharge port and a piston that expands and contracts the volume of the cylinder by the reciprocating motion that accompanies the rotation of the cylinder block.In the expansion stroke of the piston, fluid is sucked into the cylinder from the inlet side of the port block through the suction port of the valve plate, In a piston pump / motor that discharges fluid from the cylinder through the discharge port of the valve plate to the outlet side of the port block during the compression stroke of the piston, the contact surface of the valve plate with the cylinder block starts from the beginning of the suction port to the end of the discharge port. A notch groove is formed to reduce the fluctuation of the closing pressure of the cylinder toward the Since a baffle that divides the damper chamber into a damper chamber and a throttle passage that connects this damper chamber to the inlet side of the port block are provided, high-pressure fluid is drawn from the cylinder through the notch groove to the suction port when the piston 4 transitions from the compression stroke to the expansion stroke. Even if the fluid flows back to the suction port, the high-pressure fluid gradually flows from the cylinder to the port block side due to the cushioning action of the damper chamber, so the momentary collision between the high pressure and the low pressure due to the reverse flow to the suction port is mitigated, causing erosion and noise. Can be reduced.

According to the second aspect of the present invention, a valve plate having a suction port and a discharge port on a concentric circle, a cylinder block that rotates while contacting the valve plate, and a suction port and a discharge port according to a rotation angle of the cylinder block. Is equipped with a cylinder that communicates with the cylinder, and a piston that expands and contracts the volume of the cylinder by the reciprocating motion that accompanies the rotation of the cylinder block.In the expansion stroke of the piston, fluid is sucked into the cylinder from the inlet side of the port block through the suction port of the valve plate, and the piston In a piston pump / motor in which fluid is discharged from the cylinder through the discharge port of the valve plate to the outlet side of the port block during the compression stroke, from the beginning of the discharge port to the end of the suction port on the contact surface of the valve plate with the cylinder block. To form a notch groove to reduce the fluctuation of the closing pressure of the cylinder. Since a baffle partitioning the damper chamber and a throttle passage that connects this damper chamber to the outlet side of the port block are provided, high-pressure fluid flows back from the discharge port to the cylinder through the notch when the piston moves from the expansion stroke to the compression stroke. Even so, since the high pressure fluid gradually flows from the port block side to the cylinder due to the cushioning action of the damper chamber, the momentary collision between the high pressure and the low pressure due to the reverse flow to the cylinder is mitigated, and the generation of erosion and noise can be reduced. .

According to the third invention, since the bottom wall for closing the port block side of the damper chamber in the first invention or the second invention is formed on the valve plate, the bottom surface of the damper chamber is closed by the wall surface of the port block. Since it is not necessary, it is not necessary to change the passages on the inlet side and the outlet side of the port block to positions that are biased from the damper chamber to the port end side of the baffle plate.

[Brief description of drawings]

FIG. 1 is a front view of a valve plate showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part and a sectional view thereof.

FIG. 3 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 4 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 5 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 6 is an enlarged view of a main part and a cross-sectional view thereof showing another embodiment.

FIG. 7 is an enlarged view of a main part and a sectional view thereof.

FIG. 8 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 9 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 10 is an enlarged view of a main part and a cross-sectional view thereof showing another embodiment.

FIG. 11 is an enlarged view of a main part and a cross-sectional view thereof showing another embodiment.

FIG. 12 is an enlarged view of a main part and a cross-sectional view showing another embodiment.

FIG. 13 is an enlarged view of a main part and a cross-sectional view thereof showing another embodiment.

FIG. 14 is a sectional view of a piston pump / motor for explaining a conventional example.

FIG. 15 is likewise a front view of the valve plate.

[Explanation of symbols]

 2 cylinder block 3 cylinder 4 piston 5 swash plate 6 valve plate 10 suction port 11 discharge port 12, 13 V-shaped notch groove 14 baffle plate 15 to 18, 20, 21 throttle passage 30 damper chamber

Claims (3)

[Claims] 1. A valve plate having a suction port and a discharge port on a concentric circle, a cylinder block that rotates while contacting the valve plate, and a cylinder that communicates with the suction port and the discharge port according to the rotation angle of the cylinder block. Equipped with a piston that expands and contracts the volume of the cylinder by reciprocating movement due to the rotation of the cylinder block, sucks fluid from the inlet side of the port block through the suction port of the valve plate into the cylinder in the expansion stroke of the piston, and from the cylinder in the compression stroke of the piston In a piston pump / motor that discharges fluid to the outlet side of the port block through the discharge port of the plate, the closing pressure of the cylinder from the beginning of the suction port to the end of the discharge port on the contact surface of the valve plate with the cylinder block. A notch groove is formed to reduce the fluctuation of A piston pump / motor having a magic plate and a throttle passage that connects the damper chamber to the inlet side of the port block. 2. A valve plate having a suction port and a discharge port concentrically, a cylinder block that rotates while contacting the valve plate, and a cylinder that communicates with the suction port and the discharge port according to the rotation angle of the cylinder block. Equipped with a piston that expands and contracts the volume of the cylinder by reciprocating movement due to the rotation of the cylinder block, sucks fluid from the inlet side of the port block through the suction port of the valve plate into the cylinder in the expansion stroke of the piston, and from the cylinder in the compression stroke of the piston In a piston pump / motor that discharges fluid to the outlet side of the port block through the discharge port of the plate, the closing pressure of the cylinder from the beginning of the discharge port to the end of the suction port on the contact surface of the valve plate with the cylinder block. A notch groove is formed to reduce the fluctuation of A piston pump / motor which is provided with a baffle plate and a throttle passage which connects the damper chamber to the outlet side of the port block. 3. A piston pump / motor according to claim 1, wherein a bottom wall for closing the port block side of the damper chamber is formed on the valve plate.