JPH0367069A - Valve plate for pump or motor of axial piston type - Google Patents

Abstract

PURPOSE:To accomplish a simple and inexpensive manufacturing process for cylinder blocks by jointing a steel plate and Cu alloy plate together through diffusion rolling pressure contact, and thereby eliminating necessity for casting-on of steel alloy to cylinder block. CONSTITUTION:A plate of Cu alloy (phosphor bronze) 12 is jointed with a steel plate 11 by means of diffusion rolling pressure contact to constitute a valve plate. Then the Cu alloy plate 12 side is put in slide contact with a cylinder block. This prevents wear and seizure even though the cylinder block side remains in cast iron as it is. This eliminates necessity for casting-on of Cu alloy etc. to the cylinder block, which can thus be subjected to a treatment such as quenching, to lead to enhancement of the anti-pressure performance of the cylinder block.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a valve plate particularly suitable for use in a high-pressure axial piston type pump or motor.

<Prior art> For example, in a swash plate type axial piston type pump, a piston is slidably provided in a cylinder of a cast cylinder block that is rotationally driven by a shaft. The cylinder is reciprocated by the plate, and as the cylinder block slides on the valve plate, the cylinder is brought into communication with the suction port and discharge port of the valve plate.

In order to prevent wear and seizure caused by sliding between the cylinder block and the valve plate, the sliding portion of the cylinder block is made of cast-on copper alloy. This cast-on is carried out by placing a cast cylinder block main body 1 in a mold 3 and injecting molten copper alloy 2 into the upper part of the cylinder block 1, as shown in FIG.

<Problems to be Solved by the Invention> By the way, in this structure in which the sliding portion of the cylinder block is formed of copper alloy by cast-on, melting is applied onto the cast cylinder block main body l placed in the mold 3. Since the high-temperature copper alloy 2 must be injected, the cylinder block manufacturing process is complicated and costly.

Furthermore, when the molten copper alloy is cast on, the main body of the cast cylinder block 1 is dulled, so there is a drawback that the cylinder block cannot be hardened. Therefore, a cylinder block having such a structure has a disadvantage in that it has low pressure resistance and cannot be used in high-pressure pumps and motors.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the need to complicate the cylinder block manufacturing process and eliminate the need to reduce the pressure resistance of the cylinder block.

<Means for Solving the Problems> In order to achieve the above object, the valve plate for an axial piston type pump or motor of the present invention is formed by diffusion rolling and crimping a copper alloy plate to a steel plate, and has the same circular shape. It is characterized by being approximately disk-shaped with a plurality of ports on the circumference.

<Function> This valve plate is formed by diffusion rolling and pressing a temporary copper alloy onto a steel plate, so it can be easily manufactured at low cost. Furthermore, when the copper alloy plate side is brought into sliding contact with the cylinder block, wear and seizure are prevented even if the cylinder block side remains cast iron. Therefore, there is no need to cast copper alloy or the like onto the cylinder block, the cylinder block can be subjected to treatments such as hardening, and the pressure resistance of the cylinder block can be improved. therefore,
When this valve plate is used, the pressure resistance of the pump or motor is improved. Furthermore, since this valve plate has a two-layer structure of a steel plate and a copper alloy plate, the strain in the thickness direction due to pressure is smaller than that of a valve plate made of a single layer of copper alloy. Therefore, this valve plate can also be used under high pressure.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In Fig. 1, 11 is a steel plate with a thickness of 1 μm and 1 μm.
2 is an example of a copper alloy plate with a thickness of 0, 1 ++u
It is a phosphor bronze plate of n. The steel plate 11 and the phosphor bronze plate 12 are integrated by diffusion rolling and pressure bonding. Diffusion rolling crimping is a process in which a steel plate and a phosphor bronze plate are pressed together and passed through a furnace at a predetermined temperature to diffuse the phosphor bronze plate into the steel plate and firmly integrate the steel plate and the phosphor bronze plate. It is. As shown in FIG. 2, this valve plate is approximately disk-shaped and has a circular hole 10 in the center for passing the main shaft. Further, a plurality of ports 13 and 14 serving as outlet or inlet ports are provided at predetermined intervals on the circumference concentric with the circular hole 10. Note that the narrow groove 15 extending from the port 14 is a groove for preventing a sudden rise or fall in pressure near the dead center of the pump. Further, on both sides in the diametrical direction of this valve plate, mounting tabs 17 and 17 are formed, each having a cutout recess 18, 18 at the tip thereof.

A valve plate having such a structure is attached to a housing (not shown) using tabs 1717, and is attached to a phosphor bronze plate 12.
The side slides into contact with the end face of the cylinder block. Since the phosphor bronze plate 12 is in sliding contact with the end face of the cylinder block in this way,
Even if the cylinder block is made of cast iron, there is no need to cast on copper alloy or the like, so the cylinder block can be hardened or otherwise treated to improve its pressure resistance. Therefore, using this valve plate can improve the pressure resistance of the pump or motor. Furthermore, since copper alloy cast-on is not required, the manufacturing process of the cylinder block becomes simpler and cheaper, which in turn reduces the price of the pump or motor. In addition, since this valve plate has a two-layer structure of a steel plate and a phosphor bronze plate, the distortion in the wall thickness direction due to pressure of this valve plate is less than when the valve plate is manufactured with only a single layer of phosphor bronze plate. Therefore, this valve plate has less distortion even under high pressure, and can be used for high-pressure pumps, motors, etc.

In the above embodiment, a phosphor bronze plate was used as the copper alloy, but the copper alloy plate is not limited to the phosphor bronze plate, and may be a brass plate or the like.

<Effects of the Invention> As is clear from the above, the valve plate of the present invention has a two-layer structure formed by diffusion rolling and pressing a steel plate and a copper alloy plate. By making sliding contact with the cylinder block, there is no need to cast steel alloy onto the cylinder block, making the manufacturing process of the cylinder block simpler and cheaper.
The motor can be manufactured easily and at low cost, and the cylinder block can be hardened and the pressure resistance of the cylinder block can be improved, which in turn can improve the pressure resistance of the pump or motor.

In addition, this valve plate has a two-layer structure of a steel plate and a copper alloy plate, so compared to one with a single layer of copper alloy plate,
Distortion in the wall thickness direction is small, so it can be used even under extremely high pressure.

Furthermore, since this valve plate has two layers bonded together by diffusion rolling and pressure bonding, the bond is strong.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a valve plate according to an embodiment of the present invention, FIG. 2 is a front view of the valve plate according to the above embodiment, and FIG.
The figure is a schematic diagram illustrating conventional cylinder block cast-on.・Steel plate, 12... Phosphor bronze plate, l 4. Port.

Claims (1)

[Claims] (1) Formed by diffusion rolling and crimping a copper alloy plate (12) to a steel plate (11), with multiple ports (13,
14) A valve plate for a substantially disc-shaped axial piston pump or motor.