JPS59103974A - Bimetal cylinder for liquid pressure pump or motor and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent dropping of tubular member due to detouring of liquid pressure by employing tightly-contact face through plastic deformation on the inner face of body cylinder and outer face of liner then pressure fixing under coarse state. CONSTITUTION:Liquid pressure is applied from a pump or motor onto a valve board 6 to fill the opposite side of cylinder section 5 from a piston 3 with liquid pressure to detour liquid pressure to the contact-tight face between the body 8 and tubular body 9 thus to produce removing function of tubular member 9. But since the inner face of body 8 and the outer face of tubular body 9 are contacted trightly through plastic deformation while fitting state of both faces is quite coarse, removing resistance is quite high to prevent removal.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention primarily relates to the structure of a cylinder liner for a hydraulic piston pump or motor and a method for manufacturing the same. In particular, in an axial plunger pump or motor, the rotating cylinder is exposed to high pressure caused by the working fluid. 4. As a countermeasure to these requirements, -7.In general, an integral cylinder made of a copper-based alloy with bearing properties is generally used. Although it is possible that 9 mechanical strength is low and there is a limit to the working pressure,
The disadvantage is that the material costs are considerably higher than steel.

In addition, when a cast bimetallic cylinder is used, in which a copper-based bearing alloy is metallurgically bonded to the inner surface of the cylinder of an iron-based cylinder matrix, problems such as casting defects such as pinholes, segregation, and poor bonding occur.

In addition, embrittlement often occurs due to the diffusion of copper into the grain boundaries of the iron-based alloy used as the matrix, and when the matrix is
It has the disadvantage that it is difficult to adjust the metal structure by preheating to a high temperature of 0° C. or higher, which tends to cause 2-strength ratio or embrittlement, and the manufacturing cost is high. As a third countermeasure, there is a conventional method in which a sleeve made of copper-based alloy is press-fitted inside an iron-based alloy cylinder using elasticity, but in order to ensure sufficient tightness, extremely sophisticated Machining precision is required, which increases machining costs and reduces the force of tying the cylinder and sleeve together during operation.

There is also a risk that the press-fitted cylindrical sleeve may fall off.In order to solve the above-mentioned drawbacks, the present invention provides a bimetallic cylinder that is easy to manufacture and inexpensive.
The gist of "this emission" will be explained below using examples.

First, FIGS. 1 and 2, which are shown to aid understanding of the present invention, will be explained. Figure 1 shows an example of an axial plunger pump or motor, which has a rotary shaft on its end face that has bulges cut out on the same circumference and at the same intervals, and a piston (3) in each of the four hemispheres. Fit the ball part (2) at the end to connect the piston to the end surface of the rotating shaft. When the rotating shaft (2) is rotated, the piston (3) fitted into the cylinder (4) rotates and moves inside the cylinder. Every time the rotating shaft (1) makes one revolution, the piston (3) makes one reciprocating sliding movement in the cylinder part (5).This causes the working fluid to flow through the valve plate (6). It is a pump or motor that causes suction and discharge.Figure 2 shows the cylinder (4
) shows an example of the cross-sectional structure of a bimetallic cylinder in which a cylindrical body (9) made of a bearing alloy is applied as a cylinder liner to a cylinder part (5) of an iron-based alloy cylinder base body (8). be. The first invention is characterized in that a part of the inner surface of the base cylinder and the outer surface of the liner have a contact surface due to plastic deformation, which is shown in Figure 3 (
b). Figure 3 (a) shows the state of the base metal surface before the copper alloy is crimped, and Figure 3 ←) shows the state in which the bearing alloy CB) is crimped and fixed to the base metal (4) by plastic deformation. It is. In the second aspect of the invention to create such a state, holes are first formed at necessary locations in a cylinder base made of an iron-based alloy by drilling or the like. The roughness of the machined surface may be approximately 50μ to 70μ. A cylindrical body (9) made of a bearing alloy, ie, a copper-based alloy or an aluminum-based alloy, is inserted into this hole. At this time, the outer diameter of the cylindrical body (9) is 0.1 to Q, 5
It is about mm smaller. Thereafter, the pressure applied to the cylinder in the axial direction and in the tube expansion direction is applied to suppress and deform the copper-based alloy so that it protrudes by 1.5 to 5 degrees from one end of the cylinder. Pressure is applied in the axial direction by mechanical force, and in the tube expansion direction by hydraulic pressure, pneumatic pressure, etc. The inserted cylindrical body (9) of bearing alloy is formed into a base body (9) by this method.
8) Pressed against the inner surface of the cylinder, the cylindrical body (9) is expanded by plastic deformation, and the outer surface of the cylinder is closely fixed to the inner surface of the base cylinder. As shown in Fig. 3 (B), the unevenness of both the terminal surfaces of the base body and liner are perfectly matched, and the base @ (4) bearing alloy (B
) are completely adhered to each other. After all the crimping processes are completed, the inner surface of the bearing alloy is shaped by one machining process.

Next, to describe the effects of the present invention, in FIGS. 1 and 2, the hydraulic pressure of the pump or motor is controlled by the valve plate (6).
Since the side of the cylinder (5) opposite to the piston (3) is filled with hydraulic pressure, the hydraulic pressure is applied to the contact surface between the base body (8) and the cylindrical body (9), which acts to pull out the cylindrical body (9). is thought to work. The inner surface of the base body (8) and the outer surface of the cylindrical body (9) are in close contact with each other due to plastic deformation, and the fit between the projections and recesses on both surfaces is extremely rough compared to conventional press-fit bimetals, so the resistance to extraction is extremely large. Furthermore, when the present invention is applied, the inner diameter of the base body (8) is not made into a right cylindrical shape (
If the insertion end of the cylindrical body (9) is machined to have an expanded diameter as shown in the figures a) and (b), the flange part 00 will be formed at the end of the cylindrical body (9) during machining, and the cylindrical body ( The drawing resistance of the cylindrical body (9) can be made extremely large.Also, even if the inner diameter of the base body (8) is curved in the middle as shown in (c) (dJ diagram), the drawing resistance of the cylindrical body (9) can be made extremely large. It is possible to make the resistance extremely large.

Example Base material JIS 545C Base cylinder inner diameter 30am Depth: 65 fights Cylinder material JIS BO2 thickness 5mm Finished inner diameter after pressurization: 28mm Table 1 shows the relationship between the roughness of the contact surface and the punching load.

Table 1 As stated above, the present invention involves inserting a cylindrical body made of a bearing metal material such as a copper-based alloy or an aluminum-based alloy into the inner surface of a cylinder whose matrix is made of an iron-based alloy. Pressure is applied in the axial direction (insertion direction) and tube expansion direction to plastically deform the cylindrical body.The outer circumferential surface of the cylindrical body is crimped and fixed to the inner surface of the base cylinder.Since this is a bimetallic cylinder for a hydraulic pump or motor, the outer circumferential surface of the cylindrical body and When the inner surface of the base cylinder has rough irregularities, it is necessary to secure the cylinder liner by crimping it to a very high angle joint to obtain a stable cylinder liner that will not come out due to the rounding of hydraulic pressure, and to improve the processing accuracy of the contact surface during manufacturing. It is possible to obtain a pump or motor that can be manufactured at low cost without any problems and can be operated with peace of mind.

[Brief explanation of drawings]

Figures 1 and 2 are side sectional views and partial sectional views showing a part of a hydraulic pump or motor, drawn for the purpose of understanding the present invention, and Figure 3) is a surface of the base cylinder before processing. Figure 3 (Foundation) is an enlarged cross-sectional view showing the bimetal processing on the surface of the base cylinder of Figure 3B).
FIG. 4(,)(b)(C)(d) shows four examples of cross-sectional views showing embodiments of the present invention. piston, 4
... Cylinder 2.5... Part of the cylinder, 6...
Valve plate, 7...Casing, 8...Main body, 9...Cylindrical body 10...7 rung part. Patent Applicant Oka 1) Nobu Nao'$ 1 Figure v 2 Illustration 3 m

Claims (1)

[Claims] (1) In a cylinder whose matrix is made of an iron-based alloy and whose cylinder liner is made of a bearing metal feather such as a copper-based alloy or an aluminum-based alloy, the inner surface of the base cylinder and the outer surface of the liner are plastically deformed. It was characterized by having. Bimetal cylinder for hydraulic pump or motor〇(2)
A cylindrical body made of a bearing-ordered metal feather such as a copper-based alloy or an aluminum-based alloy is inserted into the inner surface of a cylinder made of an iron-based alloy, and pressure is applied to the cylindrical body in the axial direction and in the tube expansion direction. A method for manufacturing a bimetallic cylinder for a hydraulic pump or motor τ, characterized by crimping and fixing the outer circumferential surface of a plastically deformed cylindrical body to the inner surface of a base cylinder.