JPH0826858B2 - Hydraulic pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hydraulic pump that is mounted on, for example, an automobile and that is compact and generates high pressure.

"Prior Art" Conventionally, a hydraulic pump is mounted in an automobile as a component of an anti-skid device of the automobile. This conventional hydraulic pump is disclosed in Japanese Patent Application Laid-Open No.
The discharge hole 2 communicated with the pressure generating chamber 1 shown in the figure is in the stroke direction of the piston 4 on the center line of the cylinder 3, and the ball valve 5 for opening and closing the discharge port 2 opens the suction port 6 provided in the piston 4. Ball valve 7 and spring 8 to open and close
It is arranged in series with, and in this one,
After the cylinder 3 is assembled in the pump body 9, the retaining member 10 is screwed into the pump body 9.

However, in such a conventional hydraulic pump,
A suction valve (ball valve) 7, a spring 8, on the center line of the cylinder 3,
Since the discharge valves (ball valves) 5 are arranged in series, there is a drawback that the length of the cylinder 3 in the axial direction becomes long. Further, after the cylinder 3 is assembled in the pump body 9, the retaining member 10 is further removed. However, there is a problem in that the length in the axial direction is further lengthened.

Therefore, as described in Japanese Patent Application No. 61-144159, a discharge port is provided in the peripheral wall of the pressure generating chamber of the cylinder accommodating the piston so as to intersect the axial direction of the cylinder, and the discharge port is opened to the outer periphery of the cylinder. A valve body having a spherical surface or a conical surface that is in close contact with the opening and opens and closes the discharge port is provided in the opening of the discharge port, and a leaf spring that presses the valve body against the opening of the discharge port is provided. As a result, it was conceivable that the total length of the pump body in the axial direction of the cylinder was significantly shortened, the hydraulic pump as a whole was made smaller and lighter, and the installation space for both was reduced.

[Problems to be Solved by the Invention] However, in this hydraulic pump, a valve element provided at the opening of the discharge port for opening and closing the discharge port is provided at the opening of the discharge port by the urging force of the leaf spring. As the leaf spring covers the discharge port, the force of returning the valve body to the valve seat lifted by the jet flow of the liquid from the discharge port is weakened when the amount of discharged liquid increases, and the leaf spring closes. The valve operation may be delayed, and when the leaf spring operates at high speed in the liquid, the operating resistance of the leaf spring due to the liquid becomes large and the return speed of the leaf spring to the valve seat side slows down. The operation may be delayed, and when the valve body is actuated, the valve body is constrained by the leaf spring and operates in an arc shape, so the return position of the valve body is easily displaced from the center of the valve seat, and the valve body moves toward the valve seat. Since the shortest distance is not passed, the valve closing operation at high speed is delayed There was a risk that

An object of the present invention is to provide a hydraulic pump that solves the above problems.

"Means for Solving Problems" The present invention has the following configuration in order to achieve the above object. That is, in a hydraulic pump in which the piston brought into contact with the outer circumference of the eccentric cam reciprocates by the operation of the eccentric cam to generate hydraulic pressure, the cylinder in which the piston is housed has a peripheral wall of a pressure generating chamber with the cylinder A discharge port is provided in a direction intersecting with the axial direction of the cylinder, and a valve body having a spherical surface that can be brought into close contact with the opening for opening and closing the discharge port is provided at the opening of the discharge port that opens to the outer periphery of the cylinder. On the other hand, the wire is formed in a ring shape so that both ends of the wire overlap so that the wire can be expanded / contracted, and a portion opposite to the overlapping both ends of the wire and facing the both ends. A ring spring is formed by forming a ring portion having an inner diameter that prevents the valve body from passing by the wire rod, and the valve body is pressed against the opening of the discharge port by the contracting force of the ring spring. In order to prevent the movement of the ring spring in the axial direction of the cylinder by engaging the ring spring with the engaging portion provided on the outer peripheral surface of the cylinder, the valve body is fitted into the ring portion and It is characterized by being attached.

[Operation] Since the discharge port is provided on the circumferential wall of the pressure generating chamber of the cylinder in a direction intersecting with the axial direction of the cylinder, the axial length is shortened and the entire hydraulic pump is downsized. Also, since the valve body is pressed against the opening of the discharge port by the ring spring made of wire, the ring spring can be made thin regardless of the whole, and the contact area of the ring spring with the liquid is reduced to reduce the influence of the liquid flow and the operating resistance of the ring spring due to the liquid. Can be extremely small,
In addition, the valve element can be operated linearly on the center of the discharge port, and these prevent the valve element from operating delay. Moreover, since the ring spring and the valve body are separate bodies, the valve body itself that repeatedly contacts and separates from the cylinder does not need to be made of a material such as rubber that is easily elastically deformed. It is possible to improve the property.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. The hydraulic pump of the present invention comprises a motor 11 and a pump unit 12, which are generally well known.

Explaining the pump section 12, a suction chamber 14 is provided in the center of the pump body 13, and the suction chamber 14 is the first chamber.
The reservoir 15 shown in the figure is connected to the reservoir 15 via a passage 16 and a pipe. Liquid is stored in the reservoir 15. First
Through holes 18, 18 are formed on both sides of the suction chamber 14 in the drawing so as to communicate with the suction chamber 14 and to be orthogonal to the rotation shaft 17 of the motor 11. The rotary shaft 17 penetrates the partition wall 13a of the motor 11 on the pump body 13 side and faces the suction chamber 14.

An eccentric cam 19 is fixedly attached to the tip of the rotating shaft 17. A ring 21 is fitted to the eccentric cam 19 via a bearing 20. 22 is an oil seal.

Cylinder blocks 23A, 23A are fitted in the through holes 18, 18, respectively, and the cylinders 23, 23 which are the constituent members of the cylinder blocks 32A, 32A are screwed into the pump body 13. A piston 24 is slidably fitted in each cylinder 23. The piston 24 is attached to the ring 21 by a spring 25 provided between the bottom of the cylinder 23 and the piston 24.
The bottom of the cylinder 23 and the piston 24.
A pressure generating chamber 26 is formed between and. Further, the piston 24 is formed with a passage 27 penetrating its center. An opening 28 is formed at one end of the passage 27 orthogonal to the passage 27, and a valve seat 29 is formed at the other end of the passage 27. A suction valve 30, which is a ball valve, is attached to the valve seat 29.
A spring 31 provided between the cylinder 29 and the bottom of the cylinder 23 urges the valve seat 29 to the seat side.

On the other hand, an annular groove 32 is formed at a predetermined position on the outer periphery of the cylinder 23, and a discharge chamber is provided between the annular groove 32 and the pump body 13.
33 are formed. The cylinder 23 has a pressure generating chamber.
A discharge port 34 that connects the discharge chamber 33 with the discharge chamber 33 is formed.
One discharge port 34 is formed at the radial position of the cylinder 23.

The discharge chamber 33 includes a passage 36 formed in the pump body 13, piping,
Actuator (eg anti-skid device for automobile)
37, and is connected to the reservoir 15 via a relief valve 38.

A valve seat 34a is formed in the annular groove 32 of the cylinder 23 at the opening of the discharge port 34. The valve seat 34a is a spherical seat having a spherical recess. A discharge valve 39 made of a ball valve is seated on the valve seat 34a, and the discharge valve 39 is pressed toward the valve seat 34a by a ring spring 35 made of an elastic wire fitted in the annular groove 32. 3
4 can be opened and closed by the discharge valve 39.

As shown in FIGS. 3 to 5, the ring spring 35 is formed into an elliptical ring shape so that both end portions 35b, 35b of the wire material have elasticity, and the diameter of the ring spring 35 can be increased or reduced. Both ends 35b, 35b where wires overlap
A ring portion 35a formed by bending the wire is formed on the opposite side of the both ends 35b, 35b.
The inner diameter of the ring portion 35a is set to a diameter that prevents passage of the discharge valve 39 in the ring portion 35a (smaller than the maximum diameter of the discharge valve 39 in this embodiment). The portion 35b is engaged with an engaging portion (groove) 24a provided on the outer peripheral surface of the cylinder 23 so as to restrict the movement of the cylinder 23 in the axial direction, and the ring portion 35a has the above-mentioned portion. The discharge valve 39 is fitted. For this reason, the discharge valve 39 is provided with the ring spring 35 deformed.
It is pressed against the valve seat 34a at the opening of the discharge port 34 by its diameter reducing force.

The tip portions 35c, 35c of the both side portions 35b, 35b are bent outward. This tip 35c, 35c is the cylinder 23
When attaching the ring spring 35 to the outer circumference of
It serves as a handle for greatly deforming the inner diameter of 35. Further, when the discharge valve 39 opens, the both end portions 35b are deformed by the ring spring 35 and the both end portions 35b, 35b.
The b is in the engaging portion (groove) 24a so as not to slip, and is wound around the groove bottom portion of the engaging portion 24a.

In addition, the discharge chamber in FIG.
Seal rings 40, 40 are fitted on both sides of 33, and the discharge chamber 33 is isolated from the suction chamber 14 and the outside by these seal rings 40, 40. A mounting groove 41 for a rotary tool for screwing the cylinder 23 to the pump body 13 during assembly is formed at the outer end of the cylinder 23. 42 is a dustproof and waterproof cap.

Next, the operation of the hydraulic pump configured as described above will be described.

When the motor 11 is driven and the rotary shaft 17 rotates, the eccentric cam 19 rotates together with the rotary shaft 17, and the piston 24 is reciprocally moved in the axial direction by being pushed by the ring 21 via the bearing 20 and the pressure generating chamber. Change the volume of 26.

When the piston 24 moves in the direction of compressing the spring 25, the hydraulic pressure in the pressure generating chamber 26 increases, and when the hydraulic pressure becomes higher than the hydraulic pressure of the discharge chamber 33, the liquid in the pressure generating chamber 26 and the discharge port 34 becomes The discharge valve 39 is pressed radially outward of the cylinder 23 against the force of the ring spring 35 to open the discharge valve 39 and flow into the discharge chamber 33.
Reservoir 15 via passage 36, piping, actuator 37
Flows into. At this time, the suction valve 30 is in a state in which the passage 27 is closed by the force of the spring 31.

Further, since the ring spring 35 that presses the discharge valve 39 against the opening of the discharge port 34 is made of a wire material, the contact area with the liquid is small, and the influence of the jet flow spouting from the discharge port 34 on the ring spring 35 is extremely small. In addition, even when operating at high speed in the liquid, the operation resistance to the liquid is made small to prevent the operation delay of the discharge valve 39. Also,
The ring portion 3 is provided at a position facing both end portions 35b of the ring spring 35.
Since 5a is formed and the discharge valve 39 is fitted in the ring portion 35a, the discharge valve 39 operates linearly on the center of the discharge port 34. Therefore, since the discharge valve 39 moves the shortest distance,
Delay of opening and closing of the discharge valve 39 is prevented.

When the liquid pressure in the pressure generating chamber 26 is excessive, the liquid in the pressure generating chamber 26 and the discharge port 34 flows into the reservoir 15 through the relief valve 38.

Then, after the piston 24 has maximally compressed the spring 25, the spring 25 presses the piston 24 toward the eccentric cam 19 in a state of being in contact with the ring 21, thereby increasing the volume of the pressure generating chamber 26. Then, the discharge valve 39 is closed, the pressure inside the pressure generating chamber 26 decreases as the volume of the pressure generating chamber 26 increases, and finally becomes equal to or lower than the atmospheric pressure, and the differential pressure between the passage 27 and the pressure inside the pressure generating chamber 26. Causes the suction valve 30 to move away from the valve seat 29, and the passage 27
open. This allows passage from the suction chamber (atmospheric pressure) 14 to the passage 27.
The liquid is sucked into the pressure generating chamber 26 via. At this time, the discharge valve
39 remains closed. It should be noted that the discharge valve 39 needs to be quickly restored after the discharge of the liquid from the discharge port 34 to close the discharge port 34, but the discharge valve 39 is promptly moved to the opening of the discharge port 34 by the force of the ring spring 35. The discharge port 34 is surely closed by closely contacting. Further, since the ring spring 35 has its both end portions 35b, 35b engaged with the engagement portion 24a of the cylinder 23 so as not to slip, the ring spring 35 is always prevented from rotating.

As described above, the suction valve 30 and the discharge valve 39 alternately work as a one-way valve to exert the pump function. That is, one piston 24 in the pump body 13 sucks and discharges the liquid once for each rotation of the rotary shaft 17. In the left and right pistons 24 in FIG. 1, the liquid suction operation and the liquid discharge operation are performed in reverse.

Further, in this embodiment, since the discharge port 34 is provided in the peripheral wall of the pressure generating chamber 26 of the cylinder 23 orthogonal to the axial direction of the cylinder 23, the total length of the pump body 13 in the axial direction of the cylinder 23 is significantly shortened. As a result, the entire hydraulic pump has become smaller and lighter,
It requires less installation space on the vehicle,
Furthermore, since the number of parts is reduced, they can be easily assembled.

[Advantages of the Invention] According to the present invention, in a hydraulic pump that generates hydraulic pressure by reciprocating movement of a piston brought into contact with the outer periphery of the eccentric cam by the operation of the eccentric cam, in a cylinder housing the piston. A discharge port is provided on the peripheral wall of the pressure generating chamber in a direction intersecting with the axial direction of the cylinder, and the discharge port is opened at the outer periphery of the cylinder and is closely attached to the opening to open and close the discharge port. While providing a valve body having a possible spherical surface, the wire rod is formed in a ring shape so that both end sides of the wire rod overlap so that the diameter can be expanded / contracted, and the wire rod is on the opposite side of the overlapped both end portions. A ring spring formed by forming a ring portion having an inner diameter that prevents passage of the valve body by the wire is provided at a portion facing both end portions, and the valve body is provided at the opening of the discharge port. The ring spring is engaged with an engaging portion provided on the outer peripheral surface of the cylinder to restrict the movement in the axial direction of the cylinder, and the valve body is fitted into the ring portion in order to press it by a reducing force. Since it is configured to be mounted on the cylinder, the following effects are obtained.

Since the discharge port is provided in the circumferential wall of the pressure generating chamber of the cylinder in a direction intersecting with the axial direction of the cylinder, the axial length is significantly shortened, and the entire hydraulic pump can be reduced in size and weight.

Since the valve body is pressed against the opening of the discharge port by the ring spring made of wire, the ring spring can be made thin regardless of the valve body, and the contact area of the ring spring with the liquid is small, so the influence of the liquid flow is extremely small. In addition to the above, it is possible to make the operation resistance of the ring spring due to the liquid extremely small, thereby preventing the operation delay of the discharge valve.

Since a ring portion is formed on the opposite side of the both ends of the ring spring and at a position facing these both ends, and the valve body is fitted into this ring portion, the valve body is straight on the center of the discharge port. It operates, and therefore the valve body moves the shortest distance, whereby the delay in the operation of the discharge valve can be more reliably prevented.

Since the ring spring and the valve body are separate bodies, the valve body itself that repeatedly contacts and separates from the cylinder does not need to be made of a material such as rubber that is easily elastically deformed, and therefore durability can be improved. .

[Brief description of drawings]

1 to 5 show an embodiment of the present invention.
1 is a sectional view taken along line I-I of FIG. 2, FIG. 2 is a partially cutaway side sectional view, FIG. 3 is a sectional view taken along line III-III of FIG. 1, and FIG. FIG. 3 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a perspective view of a spring, and FIG. 6 is a longitudinal sectional view of essential parts showing an example of a conventional hydraulic pump. 11 …… Motor, 12 …… Pump part, 13 …… Pump body, 14
…… Suction chamber, 15 …… Reservoir, 17 …… Rotating shaft, 19 ……
Eccentric cam, 23 …… Cylinder, 24 …… Piston, 24a ……
Engagement part (groove), 26 ... Pressure generating chamber, 27 ... Passage, 30 ...
Suction valve, 32, ... annular groove, 34, discharge port, 34a, valve seat, 35, ring spring, 35a, ring part, 35b, side end, 39, discharge valve (valve element).

Claims (1)

[Claims] 1. A hydraulic pump for generating hydraulic pressure by reciprocating a piston brought into contact with the outer periphery of the eccentric cam by the operation of the eccentric cam, in a peripheral wall of a pressure generating chamber of a cylinder accommodating the piston. Is a valve having a discharge port provided in a direction intersecting the axial direction of the cylinder, and having a spherical surface that can be brought into close contact with the opening for opening and closing the discharge port at the opening of the discharge port that opens to the outer periphery of the cylinder. While the body is provided, the wire is formed in a ring shape so that both ends of the wire overlap so that the wire can be expanded and contracted, and the wire is opposite to the overlapped end of the wire and faces the end of the wire. The part is provided with a ring spring having a ring portion having an inner diameter that prevents the valve body from passing through the wire rod, and the valve body is pushed to the opening of the discharge port by the contracting force of the ring spring. For this purpose, the ring spring is engaged with an engagement portion provided on the outer peripheral surface of the cylinder to restrict movement in the axial direction of the cylinder, and the valve body is fitted into the ring portion to be attached to the cylinder. A hydraulic pump characterized by being mounted.