JPH08177752A - Liquid-operated pump - Google Patents

Abstract

PURPOSE: To easily assemble a pump housing, and prevent generation of a foreign matter at assembling time by fitting the opposed ends of a cylinder body and a plug to both ends of a cylindrical connecting member so as to temporarily fasten them to each other. CONSTITUTION: A liquid-operated pump is provided with a pump housing 23 formed by connecting a bottomed cylindrical plug 25 forming a delivery chamber 29 between it and an outside surface of its end wall 24e to a cylinder body 24 of a cylinder shape. A plunger 39 forming a pump chamber 38 leading to a suction hole 42 and a delivery hole 51 between it and an inside surface of the end wall 24e is fitted to the cylinder body 24 or the like so as to be capable of reciprocative sliding motion, and intake and delivery valves 14 and 15 are provided to open and close the suction and delivery holes 42 and 51 according to a pressure increase and reduction of the pump chamber 38. In a condition of being temporarily fastened to each other by a connecting member 26 formed in a cylindrical shape out of synthetic resin, the cylinder body 24 and the plug 25 to constitute the pump housing 23 are fitted in an installed hole 22, and assembling work is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical cylinder body having an end wall provided with a discharge hole, and a cylindrical plug having a bottom which forms a discharge chamber between the cylindrical body and the outer surface of the end wall. And a pump housing fitted and fixed in a mounting hole provided in the base body and a pump chamber communicating with the suction hole communicating with the reservoir and communicating with the discharge hole are formed between the inner surface of the end wall. A plunger that is fitted in the cylinder body so that it can slide back and forth, a discharge valve that opens and closes the discharge hole when the pump chamber increases and decreases, and a suction that opens and closes the suction hole when the pump chamber decreases and increases pressure. And a hydraulic pump having a valve.

[0002]

2. Description of the Related Art Conventionally, such hydraulic pumps have been disclosed, for example, in Japanese Utility Model Laid-Open No. 5-64481 and Japanese Patent Application Laid-Open No. 2-24974.
It is already known from the publication No. 9 and the like.

[0003]

SUMMARY OF THE INVENTION In the above conventional one,
The open end of a cylindrical plug with a bottom is caulked to the cylinder body to form a pump housing, and caulking work is required when connecting the cylinder body and the plug, and the assembling work is both complicated and caulking. Foreign matter such as burrs generated due to the operation may enter the pump housing and hinder smooth operation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic pump that facilitates the assembly of the pump housing and prevents the generation of foreign matter during assembly.

[0005]

In order to achieve the above object, the invention according to claim 1 is characterized in that a cylindrical cylinder body having an end wall provided with a discharge hole is provided between the outer surface of the end wall. It is connected to a bottomed cylindrical plug that forms a discharge chamber and is fitted and fixed in a mounting hole provided in the base body, and can communicate with a suction hole that communicates with a reservoir and communicates with the discharge hole. A plunger formed between the inner surface of the end wall and the pump chamber so as to be reciprocally slidably fitted in the cylinder body, a discharge valve for opening and closing the discharge hole according to increase and decrease in pressure of the pump chamber, and a pump chamber In a hydraulic pump equipped with a suction valve that opens and closes a suction hole in response to pressure reduction and pressure increase, opposite ends of a cylinder body and a plug are fitted to both ends of a cylindrical connecting member so as to temporarily fix them to each other. It is characterized by combining.

According to a second aspect of the invention, in addition to the structure of the first aspect of the invention, the plug has a large diameter portion fitted into the mounting hole and a small diameter portion fitted into the connecting member. An annular mounting groove which is formed into a bottomed cylindrical shape with a step formed by providing a step portion between the portions, and which is provided with an annular seal member that contacts the inner surface of the mounting hole between the end portion and the step portion of the connecting member. An annular discharge passage is formed between the base body and the pump housing, the annular discharge passage having one side along the axis of the mounting hole sealed by the annular seal member and communicating with the discharge chamber.

According to the invention of claim 3, in addition to the structure of the invention of claim 1 or 2, the connecting member is
A discharge port for communicating the discharge chamber is provided in an annular discharge passage formed between the base body and the pump housing, and a filter covering the entire surface of the discharge port is attached to the connecting member.

According to a fourth aspect of the present invention, in addition to the structure of the first, second or third aspect of the present invention, the connecting member has a discharge pipe communicating with an annular discharge passage formed between the base body and the pump housing. An outlet is provided, and a small-diameter cylindrical portion having an end wall is provided in the cylinder body by forming an annular passage communicating with the discharge port with the inner surface of the connecting member. A groove is provided extending in the radial direction of the plug, the groove forming a passage communicating with the annular passage with the outer surface of the end wall.

According to a fifth aspect of the invention, in addition to the structure of the fourth aspect of the invention, the connecting member has its discharge port arranged closer to the small-diameter cylinder portion side than the groove, and the cylinder body and the plug. A filter that is provided between and covers the entire surface of the discharge port is attached to the connecting member.

[0010]

According to the configuration of the invention described in claim 1, since the pump housing is formed only by fitting and connecting the cylinder body and the plug to both ends of the connecting member, complicated caulking work is unnecessary, No foreign matter such as burrs is generated during caulking work.

According to the configuration of the invention described in claim 2, the process for forming the mounting groove for mounting the annular seal member on the pump housing is unnecessary.

According to the configuration of the invention described in claim 3,
It is possible to prevent foreign matter from entering the pump housing when the pump housing is completely assembled, and to prevent foreign matter from flowing to the hydraulic equipment connected to the hydraulic pump when the hydraulic pump is operating. it can.

According to the configuration of the invention described in claim 4,
Since the small-diameter cylindrical portion of the cylinder body and the groove of the plug are formed during the forging of the cylinder body and the plug, a passage for communicating the discharge chamber with the annular discharge passage is formed.
It can be easily formed without performing special drilling processing on the cylinder body and the plug.

Further, according to the structure of the invention described in claim 5, the working fluid discharged from the pump chamber to the discharge chamber flows in a crank shape from the passage to the annular passage and passes through the filter, Impact of the hydraulic fluid on the filter is avoided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of the present invention. FIG. 1 is an overall hydraulic circuit diagram of an antilock brake control device, and FIG. 2 is a vertical sectional view of a hydraulic pump.

First, in FIG. 1, the master cylinder M is
An output port 6 for outputting a braking fluid pressure according to the depression of the brake pedal 5 is provided, and an antilock brake control device 7 is provided between the output port 6 and the wheel brake B.

The antilock brake control device 7 is
Reservoir 8, hydraulic pump 9 provided between reservoir 8 and output port 6 of master cylinder M, and wheel brake B are selectively switchable to output port 6 and reservoir 8 of master cylinder M and connectable. And valve means 10. Although the damper 11 and the orifice 12 are connected between the output port 6 and the hydraulic pump 9 of the master cylinder M, the damper 11 may be omitted.

The switching valve means 10 is a normally open solenoid valve V _{O provided} between the output port 6 of the master cylinder M and the wheel brake B and a normally closed solenoid valve provided between the wheel brake B and the reservoir 8. Solenoid valve V _C and normally open solenoid valve V
A one-way valve 13 that allows the flow of hydraulic fluid from the wheel brake B side to the master cylinder M side when the hydraulic pressure on the wheel brake B side is higher than the master cylinder M side is connected in parallel to _O.

The hydraulic pump 9 has a built-in suction valve 14 provided between it and the reservoir 8 and a discharge valve 15 provided between it and the output port 6 of the master cylinder M.

Referring also to FIG. 2, the hydraulic pump 9 is
It is disposed on the metal base 16. This base 1
6 is provided with a recess 21 for rotatably housing a drive cam 20 provided on a drive shaft 19 of a motor 18 attached to the base 16, and a recess 21 is provided between the recess 21 and one surface 16a of the base 16. A mounting hole 22 having an axis orthogonal to the rotation axis of the motor 18 is provided. Thus, the mounting hole 22 has first, second and third hole portions 22a, 22b, 22c which gradually increase in diameter from the concave portion 21 side,
The third hole portion 22c and the screw hole portion 22d having a diameter larger than that of the third hole portion 22c are coaxially connected to each other.
A step portion 22e is formed between c. The pump housing 23 of the hydraulic pump 9 is fitted and fixed in the mounting hole 22.

The pump housing 23 has a cylinder body 24.
And the plug 25 are connected to each other,
The cylinder body 24 and the plug 25 are fitted into the mounting hole 22 in a state where they are temporarily fixed to each other by a connecting member 26 formed of a synthetic resin in a cylindrical shape. When the cylinder body 24 and the plug 25 are temporarily fixed to each other, the opposite ends of the cylinder body 24 and the plug 25 are lightly press-fitted into both ends of the connecting member 26, for example.

The cylinder body 24 includes a fitting tubular portion 24a fitted into the first hole portion 22a of the mounting hole 22, and the fitting tubular portion 24.
A collar portion 24b that extends radially outward from the rear end (a left end in FIG. 2) of a and is abutted and engaged with the step portion 22e of the mounting hole 22.
And a small diameter cylinder extending rearward with a step formed between the connecting cylinder portion 24c and a connecting cylinder portion 24c having a diameter smaller than that of the flange portion 24b and extending rearward (leftward in FIG. 2) from the flange portion 24b. Part 2
4d and an end wall 24e provided at the rear end of the small diameter tubular portion 24d.
And has a bottomed cylindrical shape.

On the other hand, the plug 25 has a large-diameter portion 25a fitted into the third hole portion 22c of the mounting hole 22, and the cylinder body 24.
Small diameter portion 25b set to the same outer diameter as the connecting cylinder portion 24c of
And a stepped portion 25c are provided between them and are formed in a bottomed cylindrical shape with a step open to the cylinder body 24 side.

At one end of the connecting member 26, the cylinder body 2
The connecting cylinder portion 24c of No. 4 is lightly press-fitted until the collar portion 24b is brought into contact with one end of the connecting member 26. On the other end side of the connecting member 26, the small diameter portion 25b of the plug 25 is attached to the small diameter portion 2b.
It is lightly press-fitted until the end surface of 5b is brought into contact with the outer surface of the end wall 24e of the cylinder body 24.

The axial length of the connecting member 26 is the same as that of the end of the connecting member 26 and the step 25c of the plug 25 when the cylinder body 24 and the plug 25 are temporarily fixed to each other by the connecting member 26. The ring-shaped sealing member 27 is formed so that an annular mounting groove 27 is formed between the mounting holes 27, and the mounting groove 27 contacts the inner surface of the third hole portion 22c when the pump housing 23 is fitted into the mounting hole 22. 28 is attached.

A discharge chamber 29 is formed between the cylinder body 24 and the plug 25 temporarily fixed by the connecting member 26, that is, between the outer surface of the end wall 24e of the cylinder body 24 and the plug 25. An annular passage 30 is formed between the outer surface of the small-diameter cylindrical portion 24d of the cylinder body 24 and the inner surface of the connecting member 26, and a passage 31 for communicating the discharge chamber 29 with the annular passage 30 is formed on the end surface of the plug 25 on the end wall 24e side. A groove 32 formed between the plug 25 and the outer surface of the end wall 24e is provided so as to extend in the radial direction of the plug 25.

In such a pump housing 23, the fitting cylinder portion 24a of the cylinder body 24 is fitted into the first hole portion 22a and the plug 25 of the plug 25 is fitted until the flange portion 24b of the cylinder body 24 is brought into contact with the step portion 22e. The large diameter portion 25a is fitted into the mounting hole 22 so as to fit into the third hole portion 22c, and the screw hole portion 22d of the mounting hole 22 is screwed with the plug member 33 that abuts the plug 25. Then, by tightening the plug member 33 so that the collar portion 24b of the cylinder body 24 is brought into pressure contact with the step portion 22e, the pump housing 2 in a state in which the cylinder body 24 and the plug 25 are brought into contact with and joined to each other
3 is fixedly arranged in the mounting hole 22.

With the pump housing 23 fitted and fixed in the mounting hole 22, the outer surface of the cylinder body 24 and the second hole portion 2 are fixed.
An annular suction passage 34 is formed between the inner surface of 2b and the outer surface of the cylinder body 24, the plug 25 and the connecting member 26, and an annular discharge passage 35 is formed between the inner surface of the third hole portion 22c. Thus, on the outer surface of the fitting tubular portion 24a of the cylinder body 24, an annular seal member 36 that contacts the inner surface of the first hole portion 22a to seal the inner side in the axial direction of the annular suction passage 34.
Is attached. The axial outer side of the annular discharge passage 35 is sealed by an annular seal member 28 mounted in a mounting groove 27 between the plug 25 and the connecting member 26. Further, the collar portion 24b is isolated from the annular suction passage 34 and the annular discharge passage 35 by a metal seal that is in close contact with the step portion 22e over the entire circumference.

The annular suction passage 34 is the reservoir 8 (see FIG. 1).
And the annular discharge passage 35 is connected to the normally open solenoid valve V.
_O (see FIG. 1) and output port 6 of master cylinder M
(See FIG. 1).

In addition, the connecting member 26 has an annular passage 30 communicating with the discharge chamber 29, and the annular discharge passage 3 around the connecting member 26.
A plurality of discharge ports 37 ... Which communicate with 5 are provided at intervals in the circumferential direction.

A plunger 39, which forms a pump chamber 38 with the inner surface of the end wall 24e, is reciprocally slidably fitted in the cylinder body 24, and the end wall 24e and the plunger 39 are fitted.
A return spring 40 is contracted between them. As a result, the end of the plunger 39 projects from the cylinder body 24, and the drive cam 2
The outer peripheral surface of the bearing 41 mounted at 0 is always slidably contacted, and the plunger 39 is reciprocally driven in the axial direction by the rotational operation of the drive cam 20 accompanying the operation of the motor 18.

The plunger 39 is coaxially provided with a suction hole 42 which is always communicated with the annular suction passage 34 and can be communicated with the pump chamber 38 regardless of its axial reciprocating position. That is, the fitting tubular portion 24a of the cylinder body 24
Are provided with a plurality of communication holes 43, which communicate with the annular suction passage 34, at intervals in the circumferential direction. The communication holes 34 are provided between the fitting tubular portion 24a and the plunger 39 regardless of the sliding operation of the plunger 39. An annular chamber 44 is formed that is in constant communication with the annular suction passage 34 through the cylinder body 2 on the outer surface of the plunger 39 so as to seal both sides of the annular chamber 44.
The annular seal members 45 and 46, which are in sliding contact with the inner surface of 4, are mounted. Thus, the suction hole 42 is provided in the plunger 39 so as to communicate with the annular chamber 44.

The suction hole 42 is opened / closed by the suction valve 14 in response to the pressure decrease / increase in the pump chamber 38. This intake valve 1
Reference numeral 4 denotes a valve seat 48 provided at an end edge of the suction hole 42 on the pump chamber 38 side, a spherical valve body 49 which can be seated on the valve seat 48 and is housed in the pump chamber 38, and a valve seat 48. It is constituted by an end wall 24e of the cylinder body 24 and a valve spring 50 compressed between the valve body 49 by exerting a spring force for urging the valve body 49 in a seating direction.

The end wall 24e of the cylinder body 24 is provided with a discharge hole 51 which communicates with the pump chamber 38 and can communicate with the discharge chamber 29. The discharge hole 51 is used for increasing and decreasing the pressure of the pump chamber 38. The discharge valve 15 is opened and closed accordingly. Thus, the discharge valve 15 has a valve seat 53 provided at the end of the discharge hole 51 on the discharge chamber 29 side, and a spherical valve body 54 that can be seated on the valve seat 53 and is housed in the discharge chamber 29. When,
It is composed of a valve spring 55 that is compressed between the plug 25 and the valve body 54 by exerting a spring force that urges the valve body 54 in a direction to be seated on the valve seat 53.

Next, the operation of the first embodiment will be described. The cylinder body 24 and the plug 25 constituting the pump housing 23 of the hydraulic pump 9 are the same as those of the cylinder body 24 and the plug 25.
The opposite ends of 4, 25 are fitted to both ends of the connecting member 26 and temporarily fixed, and in the temporarily fixed state, they are fitted and fixed in the mounting holes 22, so that the plug 25 is caulked and coupled to the cylinder body 24 as in the conventional case. Since it is unnecessary to perform a complicated caulking operation, the assembling work of the pump housing 23 can be facilitated, and a foreign matter such as a burr due to the caulking work is not generated, so that the foreign matter enters the pump housing 23. It can also be prevented from being crowded.

Further, since the annular mounting groove 27 for mounting the annular sealing member 28 is formed between the end portion of the connecting member 26 and the step portion 25c of the plug 25, the annular sealing member 2
It becomes unnecessary to perform groove processing on the plug 25 in order to mount 8, and it is possible to contribute to a reduction in processing man-hours.

Further, between the small-diameter cylindrical portion 24d provided on the cylinder body 24 and the inner surface of the connecting member 26, the annular discharge passage 35 is provided via the discharge ports 37 provided on the connecting member 26.
An annular passage 30 communicating with the end wall 2 of the plug 25 is formed.
The groove 32 extending in the radial direction of the plug 25 on the 4e-side end surface forms a passage 31 for communicating the discharge chamber 29 with the annular passage 30 between the outer surface of the end wall 24e. Thus, the small-diameter cylindrical portion 24d of the cylinder body 24 and the groove 31 of the plug 25 can be forged, and the passages 31 and 30 for communicating the discharge chamber 29 with the annular discharge passage 35 are provided in the cylinder body 24 and the plug 25. It can be easily formed without special drilling.

FIG. 3 shows a second embodiment of the present invention, in which parts corresponding to those of the first embodiment are designated by the same reference numerals.

The cylindrical connecting member 26 for connecting the cylinder body 24 and the plug 25 to each other is provided in the plug 25 so as to form a passage 31 communicating with the discharge chamber 29 with the end wall 24e of the cylinder body 24. A plurality of discharge ports 37, which are located closer to the annular passage 30 than the groove 32, are provided at intervals in the circumferential direction, and filters 56 are mounted over the entire surface of each discharge port 37.

According to the second embodiment, it is possible to prevent foreign matter from entering the pump housing 23 when the assembly of the pump housing 23 is completed, and the hydraulic pump 9
At the time of the operation of, the foreign matter can be prevented from flowing to the hydraulic equipment side such as the normally open solenoid valve V _O connected to the hydraulic pump 9. Moreover, the hydraulic fluid discharged from the pump chamber 38 to the discharge chamber 29 flows in a crank shape from the passage 31 to the annular passage 30 and flows to the filters 56, ... Thus, the hydraulic fluid impacts the filters 56. This can be avoided, and the durability of the filters 56 can be improved, and the filtering performance can be improved by setting the mesh size of the filters 56 to be smaller.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

For example, the connecting member 26 is configured so that the convex portion provided on one of the inner surface of the connecting member 26 and the outer surface of the cylinder body 24 or the plug 25 is engaged with the concave portion provided on the other. The cylinder body 24 and the plug 25 may be fitted and connected to both ends of the. Alternatively, a retaining ring that engages with the outer end of the pump housing 23 may be fitted to the inner surface of the mounting hole 22 so that the pump housing 23 is fitted and fixed in the mounting hole 22.

[0044]

As described above, according to the first aspect of the present invention, the opposite ends of the cylinder body and the plug are fitted to both ends of the cylindrical connecting member so as to temporarily fix them to each other. Assembling work can be facilitated without the need for complicated caulking work, and foreign matter such as burrs does not occur due to caulking work, which prevents foreign matter from entering the pump housing and hindering smooth operation. can do.

According to a second aspect of the invention, in addition to the structure of the first aspect of the invention, the plug has a large diameter portion fitted into the mounting hole and a small diameter portion fitted into the connecting member. An annular mounting groove which is formed into a bottomed cylindrical shape with a step formed by providing a step portion between the portions, and which is provided with an annular seal member that contacts the inner surface of the mounting hole between the end portion and the step portion of the connecting member. Since a ring-shaped discharge passage is formed between the base body and the pump housing, the ring-shaped discharge passage being formed on one side along the axis of the mounting hole and communicating with the discharge chamber by the ring-shaped seal member is formed in the groove for mounting the ring-shaped seal member. It is possible to contribute to a reduction in processing man-hours by eliminating the need for processing.

According to the invention of claim 3, in addition to the constitution of the invention of claim 1 or 2, the connecting member is
A discharge port for communicating the discharge chamber is provided in an annular discharge passage formed between the base body and the pump housing, and a filter covering the entire surface of the discharge port is attached to the connecting member. It is possible to more reliably prevent the foreign matter from entering, and it is possible to prevent foreign matter from flowing to the hydraulic equipment side connected to the hydraulic pump when the hydraulic pump operates.

According to the invention described in claim 4, in addition to the structure of the invention described in claim 1, 2 or 3, the connecting member has a discharge pipe communicating with an annular discharge passage formed between the base body and the pump housing. An outlet is provided, and a small-diameter cylindrical portion having an end wall is provided in the cylinder body by forming an annular passage communicating with the discharge port with the inner surface of the connecting member. Since a groove is formed extending in the radial direction of the plug to form a passage for communicating the chamber with the annular passage and the outer surface of the end wall, the small diameter cylindrical portion of the cylinder body and the groove of the plug are forged. With this, it is possible to easily form the passage that allows the discharge chamber to communicate with the annular passage without performing special drilling processing on the cylinder body and the plug.

Further, according to the invention of claim 5, in addition to the configuration of the invention of claim 4, the connecting member has a cylinder body and a plug whose discharge port is arranged closer to the small-diameter cylinder than the groove. Since the filter that is provided between the discharge port and the entire surface of the discharge port is attached to the connecting member, the working fluid discharged into the discharge chamber flows in a crank shape from the passage to the annular passage and passes through the filter. Can be prevented from impacting the filter, and the durability of the filter can be improved.

[Brief description of drawings]

FIG. 1 is an overall hydraulic circuit diagram of an antilock brake control device according to a first embodiment.

FIG. 2 is a vertical sectional view of a hydraulic pump.

FIG. 3 is a vertical sectional view of a hydraulic pump according to a second embodiment.

[Explanation of symbols]

 8 ... Reservoir 9 ... Hydraulic pump 14 ... Suction valve 15 ... Discharge valve 16 ... Base body 22 ... Mounting hole 23 ... Pump housing 24 ... Cylinder body 24d ... -Small diameter cylindrical portion 24e ... End wall 25 ... Plug 25a ... Large diameter portion 25b ... Small diameter portion 25c ... Step portion 26 ... Connecting member 27 ... Mounting groove 28 ... Annular seal member 29 ... Discharge chamber 30 ... Annular passage 31 ... Passage 32 ... Groove 35 ... Annular discharge passage 37 ... Discharge port 38 ... Pump chamber 39 ... Plunger 42・ ・ ・ Suction hole 51 ・ ・ ・ Discharge hole 56 ・ ・ ・ Filter

Claims (5)

[Claims] 1. An end wall (24) provided with a discharge hole (51).
e) a cylindrical cylinder body (24) having a bottomed cylindrical plug (25) which forms a discharge chamber (29) between the cylindrical body (24) and the outer surface of the end wall (24e), and a base body ( A pump that can be communicated with a pump housing (23) fitted and fixed in a mounting hole (22) provided in 16) and a suction hole (42) that communicates with a reservoir (8) and also communicates with a discharge hole (51). A plunger (39) which is formed between the inner surface of the end wall (24e) and the chamber (38) and is fitted in the cylinder body (24) so as to be reciprocally slidable, and a pump chamber (3).
A discharge valve (15) that opens and closes the discharge hole (51) according to the increase and decrease in pressure of 8), and a suction valve (14) that opens and closes the suction hole (42) according to the decrease and increase in pressure of the pump chamber (38). ) And a cylinder body (24) and a plug (25) with opposite ends fitted to both ends of a cylindrical connecting member (26) so as to temporarily fix them (24, 25) to each other. A hydraulic pump characterized by being combined. 2. The plug (25) has a stepped portion between a large diameter portion (25a) fitted into the mounting hole (22) and a small diameter portion (25b) fitted into the connecting member (26). (25c) is formed into a stepped bottomed cylindrical shape, and a mounting hole (2) is provided between the end of the connecting member (26) and the step (25c).
An annular mounting groove (27) for mounting the annular sealing member (28) that contacts the inner surface of 2) is formed, and the mounting hole (22) is formed.
An annular discharge passage (35) which is sealed by the annular seal member (28) on one side along the axis of the and communicates with the discharge chamber (29).
A hydraulic pump according to claim 1, characterized in that it is formed between the base body (16) and the pump housing (23). 3. The connecting member (26) has a discharge port (3) for communicating the discharge chamber (29) with an annular discharge passage (35) formed between the base body (16) and the pump housing (23).
7. A hydraulic pump according to claim 1 or 2, characterized in that it is provided with 7) and a filter (56) over the entire surface of the discharge port (37) is attached to the connecting member (26). 4. The connecting member (26) is provided with a discharge port (37) communicating with an annular discharge passage (35) formed between the base body (16) and the pump housing (23), and the cylinder body (24). In the annular passage (3), a small-diameter cylinder portion (24d) having an end wall (24e) communicates with the discharge port (37).
0) is formed between the inner surface of the connecting member (26) and the end surface of the plug (25) on the side of the end wall (24e), which allows the discharge chamber (29) to communicate with the annular passage (30). (3
Groove (3) that forms (1) between the outer surface of the end wall (24e) and
2. A hydraulic pump according to claim 1, 2 or 3, characterized in that 2) is provided extending in the radial direction of the plug (25). 5. The connecting member (26) has a discharge port (3).
7) is provided between the cylinder body (24) and the plug (25) by arranging 7) closer to the small diameter cylinder portion (24d) than the groove (32), and the filter (56) over the entire surface of the discharge port (37) is a connecting member. The hydraulic pump according to claim 4, wherein the hydraulic pump is attached to (26).