JPH07103845B2 - 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. In this conventional hydraulic pump, as shown in JP-A-58-202142, the discharge port 2 communicating with the pressure generating chamber 1 shown in FIG.
A ball valve 5 for opening and closing the discharge port 2 is located in the stroke direction of the piston 4 on the center line of the ball 4 and a spring 8 for opening and closing a suction port 6 provided in the piston 4.
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, since the suction valve (ball valve) 7, the spring 8 and the discharge valve (ball valve) 5 are arranged in series on the center line of the cylinder 3, 3 has the drawback of increasing the length in the axial direction, and
Since the retaining member 10 is further screwed in after the cylinder 3 is assembled in the pump body 9, there is a problem that the axial length becomes further longer.

Therefore, as described in Japanese Patent Application No. 61-144159, a discharge port is provided on 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 on 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 at the opening of the discharge port, and a leaf spring is provided to press the valve body against the opening of the discharge port. Therefore, it was considered 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 on the vehicle 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 with an urging force of a leaf spring. Since it is pressed by, the leaf spring comes to cover the discharge port, and when the discharge liquid amount increases, the leaf spring is lifted by the jet of liquid from the discharge port and the force to return the valve body to the valve seat is weakened, The valve closing operation may be delayed, and if the leaf spring operates at high speed in 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. There is a risk that the valve may move, and when the valve body operates, the valve body is constrained by a leaf spring and operates in an arc, so the return position of the valve body is easily displaced from the center of the valve seat. Since the shortest distance to the There was a risk of delay.

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

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a hydraulic pressure that generates a 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 the pump,
A discharge port is provided on 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 in the outer periphery of the cylinder, and the discharge port is in close contact with the opening. A valve body having a spherical surface for opening and closing the discharge port is provided, and the cylinder is provided with a plate spring formed by curving a strip plate in an arc shape so that both ends thereof approach each other. By engaging the outer peripheral surface of the cylinder with the valve body at substantially the central portion in the length direction of the leaf spring to urge the valve body toward the opening of the discharge port, and In the curved surface between the portion in contact with the valve body and the both end portions, the width dimension is made smaller than the portion in contact with the valve body and the both end portions in order to reduce the area.

[Operation] Since the discharge port is provided on the circumferential wall of the pressure generation chamber of the cylinder so as to intersect with the axial direction of the cylinder and the valve is provided at the opening of this discharge port, the axial length is shortened and the entire hydraulic pump is provided. Is a miniaturized part of a strip plate curved in an arc shape, specifically, a leaf spring in which the width of the curved surface between the portion in contact with the valve body and the both ends is reduced by a notch or a hole. , The leaf spring urges and presses the valve element against the opening of the discharge port to reduce the contact area of the leaf spring with the liquid, and the influence of the liquid flow and the operating resistance of the spring due to the liquid are extremely small. In addition, the valve element is linearly operated on the center of the discharge port to prevent the valve closing delay.

[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 at the center of the pump body 13, and the suction chamber 14 is connected to the reservoir 15 shown in FIG. 1 via a passage 16 and a pipe. Liquid is stored in the reservoir 15. Through holes 18, 18 are formed on both sides of the suction chamber 14 in FIG. 1 so as to communicate with the suction chamber 14 and orthogonal to the rotation shaft 17 of the motor 11. The rotating shaft 17 is a partition on the pump body 13 side of the motor 11.
It penetrates through 13a and faces the suction chamber 14.

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

Further, the cylinder block 2 is provided in each of the through holes 18, 18.
3A and 23A are fitted together, and the cylinders 23 and 23, which are constituent members of the cylinder blocks 23A and 23A, are screwed into the pump body 13. A piston 24 is slidably fitted in each cylinder 23. The piston 24 is pressed against the ring 21 by a spring 25 provided between the bottom of the cylinder 23 and the piston 24, and a pressure generating chamber 26 is formed between the bottom of the cylinder 23 and the piston 24. There is. Further, the piston 24 is formed with a passage 27 penetrating its center.
At one end side of this passage 27, an opening 28 is formed orthogonally to this 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 installed on the valve seat 29.
And a bottom portion of the cylinder 23, a spring 31 provided between the valve seat 29 and the bottom of the cylinder 23 urges the valve seat 29 to the seat.

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 33 is provided between the annular groove 32 and the pump body 13.
Are formed. The cylinder 23 has a pressure generating chamber 26
A discharge port 34 that communicates with the discharge chamber 33 is formed. This discharge port 34 is located at the radial position of each cylinder 23, 23.
Is formed.

The discharge chamber 33 includes a passage 36 formed in the pump body 13, pipes, and an actuator (for example, an anti-skid device for an automobile) 3
7, 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 (valve body) 39 formed of a ball valve is seated on the valve seat 34a.

The discharge valve 39 is biased and pressed toward the valve seat 34a by a leaf spring 35 formed of a band plate curved in an arc shape fitted in the annular groove 32, and the discharge port 34 can be opened and closed by the discharge valve 39. It is said that.

The leaf spring 35 is formed as shown in FIGS. That is, the strip-shaped plate spring member is curved in an arc shape and its both ends 35a, 35a are brought into a butted state, and between these both ends 35a, 35a and the opposite side parts of these both ends 35a, 35a. In order to reduce the area of the curved surface of the leaf spring 35, both sides in the width direction are notched so that both ends 35a, 35a
The band-shaped portions 35b, 35b are narrower. Both end portions 35a, 35a of the leaf spring 35 are substantially rectangular, the opposite side portions of these both end portions 35a, 35a are substantially circular, and a hole 35c is formed in the center of this portion to serve as a valve pushing portion 35d. . As a result, the area of the curved surface of the leaf spring 35 is considerably reduced as compared with the case where the leaf spring including the strips having the widths of the both ends 35a, 35a is used. The leaf spring 35 is punched and bent by press working, and the widths of both end portions 35a, 35a of the leaf spring 35 and the diameter of the valve pushing portion 35d are slightly smaller than the groove width of the annular groove 32.

The hole diameter of the hole 35c is set such that a part of the valve body of the discharge valve 39 is fitted but the passage of the valve body is blocked.
The valve body of the discharge valve 39 is fitted into the inside of the leaf spring 35. Both ends 35a, 35a of the leaf spring 35 are engaged with the bottom of an annular groove 32 formed in the cylinder 23. Therefore, the valve body of the discharge valve 39 is urged and pressed against the valve seat 34a at the opening of the discharge port 34 by the plate spring 35 in a state where the plate spring 35 is deformed.

Further, when the discharge valve 39 opens, these both end portions 35a, 35
The leaf spring 35 is deformed and the discharge valve 39 is opened without slipping a. Both side portions of the strip-shaped portions 35b, 35b of the leaf spring 35 in the width direction also serve as liquid passages.

Further, the discharge chamber 33 in FIG.
Sealing rings 40, 40 are fitted on both sides of the discharge chamber 33, and the discharge chamber 33 is isolated from the suction chamber 14 and the outside by these sealing 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 outward in the radial direction of the cylinder 23 against the force of the leaf spring 35 to open the discharge valve 39, flow into the discharge chamber 33, and pass through the passage 3
6, It flows into the reservoir 15 via the pipe and the actuator 37. At this time, the suction valve 30 moves the passage 27 by the force of the spring 31.
Is closed.

Further, the leaf spring 35 that presses the discharge valve 39 against the opening of the discharge port 34 includes both end portions 35a and 35a and both end portions 35a and 35a.
Both sides in the width direction of the portion between the opposite side of the is notched to form strip-shaped portions 35b, 35b narrower than both end portions 35a, 35a, the area of the curved surface of the leaf spring 35, Since the leaf spring consisting of strips of width 35a, 35a is used, it is much smaller than that of the leaf spring.Therefore, the contact area between the leaf spring 35 and the liquid is small, and jetting from the discharge port 34 to the leaf spring 35 occurs. The influence of the jet flow is extremely small, and the operation resistance to the liquid is small even when operating at high speed in the liquid, thereby preventing the operation delay of the discharge valve 39.

In addition, the valve pushing part 3 on the opposite side of the both ends 35a, 35a of the leaf spring 35
The valve body of the discharge valve 39 is fitted into the hole 35c formed in 5d, and the discharge valve 39 is held from both sides thereof, and the width of both end portions 35a, 35a of the leaf spring 35 and the valve pushing force. Part 35d
Since the diameter of is slightly smaller than the groove width of the annular groove 32,
When assembling the leaf spring 35, the leaf spring 35 does not fall and the discharge valve 39
At the time of operation, the discharge valve 39 operates linearly on the center line 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 piston 24 is pressed toward the eccentric cam 19 side by the spring 25 while the piston 24 is in contact with the ring 21, and the pressure generation chamber 26
Increase the volume of. 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. As a result, the suction valve 30 is separated from the valve seat 29, and the passage 27 is opened. As a result, the liquid is sucked from the suction chamber (atmospheric pressure) 14 into the pressure generating chamber 26 through the passage 27.
At this time, the discharge valve 39 remains closed.

The discharge valve 39 needs to be quickly restored to close the discharge port 34 after the liquid has been discharged from the discharge port 34.
The force of the plate spring 35 causes the plate 39 to promptly come into close contact with the opening of the discharge port 34, thereby securely closing the discharge port 34. Further, since the leaf spring 35 has its both ends 35a, 35a engaged with the annular groove 32 of the cylinder 23 so as not to slip, it 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 hydraulic pump as a whole can be made smaller and lighter, the space for mounting it on the vehicle can be reduced, and the number of parts can be reduced, so that they can be easily assembled.

In the above embodiment, both end portions 35a, 35a of the leaf spring are
And a portion between these opposite end portions 35a, 35a and the opposite side portion thereof, the both end portions 35a, 35a
Although the strip-shaped portions 35b, 35b having a width narrower than that of 35a are used, the strip-shaped portions 35b, 35b are not limited to this. For example, as shown in FIG. A large number of circular holes (punching holes) 52 may be arranged in a row in the length direction to form a leaf spring 53. The circular holes 52 also serve as liquid passages.

[Advantages of the Invention] The present invention relates to a hydraulic pump that generates hydraulic pressure by reciprocating a piston brought into contact with the outer circumference of an eccentric cam when the eccentric cam operates, and the pressure generation of a cylinder accommodating the piston. A valve having a discharge port provided on the peripheral wall of the chamber so as to intersect with the axial direction of the cylinder, and having a spherical surface at the opening of the discharge port opening to the outer periphery of the cylinder, which is in close contact with the opening and opens and closes the discharge port. A body is provided, and the cylinder is provided with a leaf spring formed by bending a strip plate in an arc shape so that both ends thereof approach each other. The both ends of the leaf spring are engaged with the outer peripheral surface of the cylinder. By contacting the valve element at the substantially central portion in the length direction of the leaf spring to urge the valve element toward the opening of the discharge port, and the portion of the leaf spring that contacts the valve element and Curved odor between both ends Then, in order to reduce the area, the width dimension is made smaller than the portion in contact with the valve body and the both end portions, so that the entire length of the entire pump in the axial direction of the cylinder is significantly shortened,
The hydraulic pump as a whole is smaller and lighter, requires less space to mount it on the vehicle, and because the number of parts is reduced, it is easy to assemble them, and the valve body is not required to open the discharge port. Since the area of the curved surface of the leaf spring is reduced by providing a notch or a punched hole at a predetermined position on the plate spring to narrow the width, the positive area of this leaf spring and the liquid is small. Therefore, the influence of the liquid flow on the leaf spring can be made extremely small, and the operating resistance of the leaf spring against the liquid can be reduced even at high speed operation of the leaf spring in the liquid, thereby preventing the operation delay of the discharge valve. it can. Further, since both ends of the leaf spring are engaged with the outer peripheral surface of the cylinder and the leaf spring biases the valve element toward the opening of the discharge port, the valve element should be linearly operated on the center line of the discharge port. Therefore, the valve element can be moved by the shortest distance, and thus delays in valve opening and closing can be reliably prevented. Further, since the leaf spring can be punched and bent by press working, the leaf spring can be mass-produced and the leaf spring having uniform spring characteristics can be manufactured.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention.
1 is a sectional view taken along the line I-I of FIG. 2, FIG. 2 is a partially cutaway side sectional view, FIG. 3 is an enlarged sectional view of a main part, and FIG. 4 is IV-IV of FIG. FIG. 5 is a perspective view of a leaf spring, FIG. 6 is a perspective view of a leaf spring showing another embodiment of the present invention, and FIG. 7 is a main part showing an example of a conventional hydraulic pump. FIG. 11 …… Motor, 12 …… Pump part, 13 …… Pump body, 14
…… Suction chamber, 15 …… Reservoir, 17 …… Rotating shaft, 19 ……
Eccentric cam, 23 ... Cylinder, 24 ... Piston, 26 ... Pressure generating chamber, 27 ... Passage, 30 ... Suction valve, 32, ... Annular groove, 34 ... Discharge port, 34a ... Valve seat, 35,53 …… Leaf spring, 35
a …… End, 35b …… Strip, 35c …… Hole, 39 …… Discharge valve (valve body).

Claims (3)

[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. A discharge port is provided so as to intersect with the axial direction of the cylinder, and a valve body having a spherical surface that is in close contact with the opening and opens and closes the discharge port is provided at the opening of the discharge port that opens to the outer periphery of the cylinder. The cylinder is provided with a plate spring formed by bending the strip plate in an arc shape so that both ends thereof approach each other, and the plate spring is formed by engaging both end portions with the outer peripheral surface of the cylinder. A portion of the leaf spring that contacts the valve body and urges the valve body toward the opening of the discharge port at a substantially central portion in the length direction, and a portion of the leaf spring that contacts the valve body and the both ends. Reduce the area on the curved surface between In order to, hydraulic pump, characterized in that the width dimension than the portion and the both end portions in contact with the valve body is small. 2. A width dimension is reduced by notching a side portion of the curved surface.
The hydraulic pump according to the item. 3. The hydraulic pump according to claim 1, wherein the width dimension is reduced by providing a hole in the curved surface.