JPH07310825A - Shoe structure for hydraulic pump, etc. - Google Patents

Abstract

PURPOSE:To provide not only given sliding ability but also an excellent pull-off strength and given durability when coupling is effected under arrangement of a spherical coupling structure at the tip of a piston. CONSTITUTION:In the shoe structure of a hydraulic pump having a shoe 10 coupled under arrangement of a spherical coupling structure at the tip of a piston 1 and brought into slide contact with a swash plate 2, a slide contact part 11 brought into the swash plate 2 which forms the front side of the shoe 10 is formed of bronze and a portion 12 of which the spherical coupling structure forming the back side of the shoe 10 consists is formed of a steel. The portion 12 of which the spherical coupling structure consists is formed integrally with a slide contact 11 and the portion 12 of which the spherical coupling structure consists and the slide contact part 11 are integrally formed through a portion the diameter (d) of which is set to a value lower than the diameter D of the piston 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a shoe structure in a hydraulic pump or the like.

[0002]

2. Description of the Related Art In hydraulic equipment, for example, a hydraulic pump utilizing a swash plate, a so-called shoe in which a piston is in contact with a swash plate while a piston is provided at a tip end of the ball joint structure. It is formed to discharge oil by operating a pump.

Therefore, the shoe is required to have a predetermined slidability at its sliding contact portion because it is slidably contacted with the swash plate, and at the time of forming the ball joint structure. The part is required to have a predetermined durability.

By the way, the ball joint structure is composed of a steel ball portion and a holding portion for holding the ball portion.
The open end is crimped and formed so as to hold the sphere inside.

Since the ball made of steel cannot be welded to so-called copper, when the shoe is connected to the piston by the ball joint structure, the ball is conventionally provided on the piston side and the holding part is provided on the shoe side. It is supposed to be formed.

Therefore, in this type of shoe, conventionally, the sliding contact portion which is slidably contacted with the swash plate is formed of bronze which facilitates ensuring the slidability, and the holding portion in the ball joint structure. It is said that the portion forming the, that is, the portion forming the ball joint structure is formed of copper so that the caulking process is easy.

In order to secure the integrity between the bronze and the copper in this case, various measures such as sintering rolling, casting, brazing, fixing in the furnace, etc. are taken,
Among them, sintered rolling is most widely used.

Incidentally, an annular or disc-shaped base material having a predetermined size is punched from a base material (plate material) obtained by sintering and rolling, and the base material is further cut. Is molded into a predetermined shoe shape.

Therefore, in the conventional shoe structure, while the predetermined slidability at the slidable contact portion slidably contacting the swash plate can be easily ensured, the holding portion, that is, the portion forming the ball joint structure is As compared with the case where it is made of steel, there is a disadvantage that the holding portion cannot secure a predetermined durability.

The present invention was devised in view of the above-mentioned circumstances. The object of the present invention is not only to have a predetermined slidability but also to have a ball joint structure at the tip of the piston. (EN) Provided is a shoe structure for a hydraulic pump or the like, which has excellent withdrawal strength and has a predetermined durability when it is connected to an existing vehicle, and is optimal for use in a hydraulic pump or the like using a swash plate.

[0011]

In order to achieve the above object, the structure of the present invention is basically the shoe which is connected to the tip of the piston under the distribution of the ball joint structure and slidably contacts the swash plate. In a shoe structure of a hydraulic pump or the like having the above, a sliding contact portion that is on the front side of the shoe and is slidably contacted with the swash plate is formed of bronze, and is formed on the back side of the shoe to form a ball joint structure The part to be formed is made of steel, the part forming the ball joint structure is integrated with the sliding contact part, and the diameter of the part for forming the ball contact structure forming part and the sliding contact part is It is assumed that the diameter is set to be smaller than the diameter of the piston.

The integration of the portion forming the ball joint structure and the sliding contact portion is performed by caulking or screwing from the side of the sliding contact portion or the portion forming the ball joint structure, and the sliding contact portion and the ball joint structure. It is assumed that either split ring fastening for disposing the split ring between it and the portion forming the ball joint or press-fitting of the portion forming the ball joint structure into the sliding contact portion, or a combination thereof.

[0013]

Therefore, the shoe integrally has steel on the so-called back side of the sliding contact portion formed of bronze, and the steel can be set as the portion forming the ball joint structure.

In this case, the portion of the shoe forming the ball joint structure, that is, the portion made of steel is the base portion for welding the ball portion made of steel and constituting the ball joint structure,
Alternatively, the open end is caulked to be a holding part for holding the sphere inside.

Further, the diameter of the sliding contact portion and the portion forming the ball joint structure is designed to be smaller than the diameter of the piston, thereby forming the ball joint structure from the piston side. The force that pushes the part against the sliding contact part acts preferentially.

As a result, the sliding contact portion will not be separated from the portion forming the ball joint structure even if the integration force at the portion for integration is small.

When the portion forming the ball joint structure and the sliding contact portion are integrated by caulking or screwing from the sliding contact portion side or the portion side forming the ball joint structure, the integration is performed. Greater reliability.

In the case where the portion forming the ball joint structure and the sliding contact portion are integrated with each other to form the split ring fastening in which the split ring is arranged between the sliding contact portion and the portion forming the ball joint structure. In addition, the man-hours required to form the ball joint structure and the sliding contact portion are reduced.

Further, when the portion forming the ball joint structure and the sliding contact portion are integrated by press-fitting the portion forming the ball joint structure into the sliding contact portion, the integration can be performed quickly.

Further, when the above-mentioned respective means for integration are combined, the reliability for integration is increased in addition to the individual advantages.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the illustrated embodiments. The shoe structure according to the present invention is basically a piston 1 of a hydraulic pump or the like as shown in FIG. The swash plate 2 is connected to the tip under the distribution of the ball joint structure.
It has a shoe 10 which is slidably contacted with.

In the shoe 10, according to the present invention, the sliding contact portion 11 to the swash plate 2 is formed of bronze, and
It is assumed that the portion 12 forming the ball joint structure is made of steel, and that the portion 12 forming the ball joint structure is integrated on the back side of the sliding contact portion 11.

In the illustrated example, the portion 12 forming the ball joint structure is set to the base portion 13 for welding the ball portion 3 made of steel forming the ball joint structure by projection welding or the like.

Further, in the illustrated example, the portion 12 forming the ball joint structure and the sliding contact portion 11 are integrated by caulking fixation from the sliding contact portion 11 side, as will be described later. In the case of caulking fixation, there is an advantage in that the reliability of the integration is increased.

On the other hand, the shoe 10 has a diameter at a portion 12 forming a ball joint structure with the sliding contact portion 11, that is, a portion intended to be integrated with the base portion 13, that is, a portion to be caulked and fixed in the illustrated example. It is assumed that d is set to be smaller than the diameter D of the piston 1.

As a result, between the sliding contact portion 11 and the base portion 13, a force for pressing the base portion 13 from the piston 1 side to the sliding contact portion 11 acts preferentially, and the above-mentioned integrated force is exerted. That is, even if the caulking force is small, the sliding contact portion 11
Are no longer separated from the base 13.

In the shoe 10, the portion 12 forming the ball joint structure, that is, the base portion 13 is arranged on the back side of the sliding contact portion 11 so as to be integrated with the sliding contact portion 11 and the sliding contact portion 11. The base portion 13 is formed as follows in this embodiment.

First, the sliding contact portion 11 is, as shown in FIG.
A disc-shaped body having an appropriate thickness is provided with a recess 11a formed in a circular shape in plan view and having an appropriate depth in the center of the disc-shaped body, and the recess 11a is provided on the outer peripheral side of the disc-shaped body with an appropriate interval. It has an annular groove 11b formed to have an appropriate width and depth so as to surround it.

It should be noted that the depth of the annular groove 11b is preferably approximately the same as the depth of the recess 11a.
It is preferable that the depth is slightly deeper, and the depth is slightly deeper so that the effect of caulking, which will be described later, becomes greater.

Next, as shown in FIG. 3, the base portion 13 has a disc shape having an appropriate thickness so that the lower half side thereof is inserted into the recess 11a in a state close to the fitted state. It is formed of a body, and has a deformed portion 13a on the outer periphery on the lower half side thereof, and has a curved concave portion 13b at the center of the upper surface thereof.

The deformable portion 13a is inserted such that the lower half side of the base portion 13 is close to the fitted state in the recess 11a of the sliding contact portion 11, and the inner periphery of the recess 11a is formed by caulking from the sliding contact portion 11 side which will be described later. It is provided to increase the pull-out resistance at the contact portion when the surfaces are brought into close contact with each other.

Therefore, as long as the pull-out resistance is increased, the shape of the deformed portion 13a is not particularly limited, and is formed by cutting in the circumferential direction on the lower half side of the base 13 as shown in the illustrated example. A spiral groove may be used instead of a plurality of circumferential grooves, and although not shown, a plurality of grooves formed by cutting the lower half side of the base 13 in the circumferential direction at appropriate intervals. It may be composed of individual concave portions.

When the shape of the deformed portion 13a is a spiral groove or a spiral groove, there is no great difference in the magnitude of the pull-out resistance, but in forming it, the spiral groove can be formed more easily than the spiral groove. Will be advantageous.

Further, when the deformed portion 13a is formed as a plurality of concave portions, it is advantageous in that it can be formed in a shorter time than in the case of forming the circumferential groove or the spiral groove.

The curved concave portion 13b is formed so as to make the ball portion 3 stand still at a predetermined position when the ball portion 3 constituting the ball joint structure is welded to the base portion 13 by projection welding or the like. As long as the curved curvature matches the curvature of the spherical portion 3, its size, that is, the depth is freely selected.

As long as the spherical portion 3 is stationary at the center of the upper surface of the base portion 13, a free-form concave portion is formed in place of the curved concave portion 13b, but the curved concave portion 13b is formed as follows.
The curved concave portion 13b is preferable in order to make it a relatively easy category and to reduce the cost of parts.

Further, as a result, the ball portion 3 is replaced by the base portion 1.
3 need only be welded by projection welding or the like, and thus the formation of the curved concave portion 13b may be omitted, and in the case where the formation of the curved concave portion 13b is omitted, the It is advantageous in reducing the number of steps.

The sliding contact portion 11 and the base portion 13 formed as described above are integrated as shown in FIG.

That is, first, the lower half side of the base 13 is inserted into the recess 11a of the sliding contact portion 11 arranged on the appropriate base B in a state close to the fitted state.

From the above state, the upper jig T is lowered to
The wedge portion T1 of the jig T is pushed into the annular groove 11b formed in the sliding contact portion 11.

The jig T is formed so that the outer peripheral surface of the sliding contact portion 11 has a receiving portion T2 of which the inner peripheral surface is adjacent, so that the wedge portion T1 is pushed into the annular groove 11b. In this case, the receiving portion T2 is set to be in a so-called backup state from the outer peripheral side of the sliding contact portion 11.

By lowering the jig T, the annular groove 11b
Will be expanded by pressing the wedge part T1. At this time,
Since the receiving portion T2 prevents the outer peripheral side of the sliding contact portion 11 from bulging outward, the inner peripheral side of the sliding contact portion 11 bulges toward the outer peripheral side of the base portion 13.

As a result, the deformed portion 13a formed on the outer periphery of the lower half side of the base 13 comes to bite into the inner peripheral surface of the recess 11a, and the integration of the base 13 and the sliding contact portion 11 is realized.
At this time, separation of the base portion 13 and the sliding contact portion 11, that is, withdrawal of the base portion 13 from the sliding contact portion 11 is prevented.

As shown in FIG. 5, in the curved recess 13b of the base 13 integrated with the sliding contact portion 11 as described above, the ball portion 3 constituting the ball joint structure is placed and projection welding or the like is performed. Is welded in.

As described above, in the shoe 10 in which the ball portion 3 constituting the ball joint structure is welded, the ball portion 3 has the piston 1
As shown in FIG. 1, the piston 1 is connected to the piston 1 under the distribution of the ball joint structure by being caulked at the open end of the ball joint structure.

Therefore, in the shoe structure of the present invention formed as described above, the ball portion 3 forming the ball joint structure.
Can be integrally connected to the shoe 10 side, and the ball portion 3 can be held at the tip of the piston 1, so that the ball joint structure can be expected to have a predetermined durability, and the shoe 10 can be attached to the tip of the piston 1. It will surely be connected.

Further, as described above, in the shoe structure of the present invention, the shoe 10 is constructed to integrally have steel on the back side of the sliding contact portion 11 formed of bronze. Instead of the embodiment, as shown in FIG. 6, it becomes possible to set the above-mentioned steel in the holding portion 14 that constitutes the ball joint structure.

Then, the ball portion 3 constituting the ball joint structure is present inside the holding portion 14, and the open end 14a of the holding portion 14 is provided.
By caulking, the shoe 10 can be connected to the tip of the piston 1 via the ball joint structure, and at this time, the ball joint structure can be expected to have a predetermined durability.

In the case of the embodiment in which the steel on the back side of the sliding contact portion 11 is set as the holding portion 14 constituting the ball joint structure, the shoe 10 can be diverted as it is to the conventional shoe structure of this type. Is advantageous in that

7 to 10 show the sliding contact portion 11 and the base portion 13.
Other examples of integration with the above are shown respectively, and each example will be briefly described below.

First, in the embodiment shown in FIG. 7, the base portion 13 is integrated with the sliding contact portion 11 by caulking and fixing from the base portion 13 side.

A shaft portion 13c to be caulked is previously formed on the base portion 13, and the slide contact portion 11 has the shaft portion 13c.
A hole 11c for inserting c is preliminarily drilled, and further, a recess 11d for allowing the caulking deformation portion 13d of the shaft portion 13c to be present.
Are formed in advance.

Therefore, in this embodiment, it is indispensable to form the annular groove 11b in the sliding contact portion 11 in order to perform the crimping from the sliding contact portion 11 side in the above-mentioned embodiment. This is advantageous in that the annular groove 11b need not be formed, and therefore the durability of the sliding contact portion 11 is not deteriorated.

Further, in this embodiment, the shaft portion 13c is formed in the base portion 13 and the hole 11c is opened in the sliding contact portion 11. However, in comparison with the above-mentioned embodiment, a so-called component is used. This is advantageous in that the pre-processing in step 1 is easy.

In this embodiment, the recessed portion 11d of the sliding contact portion 11 is a portion that allows oil to enter, so that lubricating oil is interposed between the swash plate 2 and the sliding contact portion 11. This is also advantageous in that the slidability of the shoe 10 with respect to the swash plate 2 can be better maintained.

Next, in the embodiment shown in FIG. 8, the sliding contact portion 11 and the base portion 13 are integrated by screwing.

A screw hole 13e is formed in the base portion 13, a screw shaft 11e screwed into the screw hole 13e is formed in the sliding contact portion 11, and a sliding contact portion is formed. Part 11
It is supposed that the screwing operation portion 11f that opens into the concave portion 11d formed in is formed.

Therefore, this embodiment is advantageous in that, unlike the above-described caulking process, a so-called large-sized tool is not necessary for assembling the parts, and the parts can be easily assembled by using a simple tool. .

Further, in the embodiment shown in FIG. 9, the sliding contact portion 11 and the base portion 13 are integrated to form a split ring fastening by using the split ring 15.

The split ring 15 is urged to expand, and is housed in an annular groove 13f formed in the outer periphery of the lower half of the base 13 so as to resist the urging force. When distributed in the recess 11a of the sliding contact portion 11 in this state, the sliding contact portion 11 is expanded so as to be also present in the annular groove 11g formed on the inner circumference of the sliding contact portion 11.

Therefore, in this embodiment, the split ring 15 as a component is indispensable, but it is advantageous in that the assembling work is extremely easy.

Furthermore, in the embodiment shown in FIG. 10, the sliding contact portion 1
1 and the base 13 are integrally formed with the base 13 with respect to the sliding contact portion 11.
It is said that it is press-fitted.

Therefore, in this embodiment, the sliding contact portion 1
Although there is a disadvantage that so-called accuracy control is likely to be required for the formation of 1 and the base portion 13, it is advantageous in that the number of processing steps and the number of parts are significantly reduced as compared with any of the above-mentioned embodiments.

In each of the above-described embodiments, the base 13 and the sliding contact portion 11 are integrated from the sliding contact portion 11 side or the base portion 1.
When caulking or screwing from the 3 side, reliability for the integration is increased.

When the split ring 15 is used to integrate the base portion 13 and the sliding contact portion 11 or the press-fitting is performed,
Compared to the above, the reliability for integration cannot be increased.

However, in the present invention, the sliding contact portion 11
Does not have to be afraid of leaving the base 13.
Even with the split ring 15 and the press-fitting described above, the shape of the shoe 10 during use can be sufficiently maintained.

When the base portion 13 and the sliding contact portion 11 are integrated, if the integration method in each of the above-mentioned embodiments is appropriately selected and these are combined, the reliability can be further increased. It will be.

In each of the embodiments shown in FIGS. 6 to 10, although not shown, the sliding contact portion 11 and the base portion 13 which is the portion 12 forming the ball joint structure or the holding portion 14 are integrated. Of course, the diameter d is set to be smaller than the diameter D of the piston 1.

Further, in each of the above-mentioned embodiments, when the oil hole for circulating the lubricating oil is opened in the ball portion 3 forming the ball joint structure, the shoe 10, that is, the base portion 13 and It goes without saying that an oil hole communicating with the oil hole may be opened in the sliding contact portion 11.

[0070]

As described above, according to the present invention, since the sliding contact portion of the shoe, which comes into sliding contact with the swash plate, is made of bronze, it is of course possible to ensure a predetermined slidability. Since the portion forming the ball joint structure is made of steel and the portion forming the ball joint structure is integrated with the sliding contact portion, the portion forming the ball joint structure is formed as a ball joint structure. It can be set to either the base portion for welding the constituting ball portion or the holding portion which has the open end that is caulked to hold the ball portion therein. There is an advantage that the rigidity can be increased and the durability can be improved.

According to the present invention, the diameter of the shoe is set to be smaller than the diameter of the piston at the portion where the portion forming the ball joint structure and the sliding contact portion are to be integrated. The force that pushes the part that forms the ball joint structure from the piston side to the sliding contact part has priority, and as a result, the part that forms the ball joint structure and the sliding contact part are integrated. There is an advantage that the sliding contact portion is not separated from the portion forming the ball joint structure even if the integration force in the intended portion is small.

At this time, when the integration of the portion forming the ball joint structure and the sliding contact portion is caulking or screwing from the sliding contact portion side or the portion side forming the ball joint structure, There is an advantage that reliability for integration can be increased.

In the case where the split ring is fixed between the sliding contact portion and the portion forming the ball joint structure, or the portion forming the ball joint structure is press-fitted into / out of the sliding contact portion. However, there is an advantage that the assembling work becomes extremely easy, or the number of processing steps and the number of parts are significantly reduced.

In the integration of the portion forming the ball joint structure and the sliding contact portion, when the above-mentioned integration methods are appropriately selected and combined, the integration further increases the reliability. There is an advantage that it is possible to set the sex.

Therefore, according to the present invention, it is possible to obtain a shoe which has a predetermined slidability and durability and which is inexpensive and effective in use, and can be used in a hydraulic pump or the like. It has the advantage of being optimal.

[Brief description of drawings]

FIG. 1 is a diagram showing a usage state of a shoe structure according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a sliding contact portion forming a shoe.

FIG. 3 is a vertical cross-sectional view showing a base portion that is a portion that forms a shoe and forms a ball joint structure.

FIG. 4 is a view showing a mode of caulking processing in which a base portion is integrated with a sliding contact portion.

FIG. 5 is a view showing a state in which a ball portion forming a ball joint structure is welded to a base portion.

FIG. 6 is a vertical sectional view showing another embodiment of the shoe.

FIG. 7 is a vertical sectional view showing another embodiment of the shoe.

FIG. 8 is a vertical sectional view showing another embodiment of the shoe.

FIG. 9 is a vertical sectional view showing another embodiment of the shoe.

FIG. 10 is a vertical sectional view showing another embodiment of the shoe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston 2 Swash plate 3 Ball part which comprises a ball joint structure 10 Shoe 11 Sliding contact part 12 The part which forms a ball joint structure 13 Base part as a part which forms a ball joint structure 14 Retention as a part which forms a ball joint structure Part 15 Split ring d Diameter of integrated part D Piston diameter

Claims (2)

[Claims] 1. A shoe structure in a hydraulic pump or the like having a shoe connected to a tip of a piston under the distribution of a ball joint structure and slidably contacting a swash plate. The sliding contact part that is in sliding contact is formed of bronze, and the part that forms the ball joint structure on the back side of the shoe is formed of steel, and the part that forms the ball joint structure is integrated with the sliding contact part. And a shoe structure in a hydraulic pump or the like, in which the diameter of the portion forming the ball joint structure and the portion for integrating the sliding contact portion is set to be smaller than the diameter of the piston 2. The integration of the portion forming the ball joint structure and the sliding contact portion is one of caulking fixing or screwing, split ring fastening and press fitting, or a combination thereof. Shoe structure in hydraulic pump etc.