JPH0932721A - Plunger pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a plunger pump light and compact, in a plunger pump in which one end of a plunger is faced to a pump room and inserted to a pump housing slidably and also a drive means for giving the push-press force to the direction for reducing the volume of the pump room to the plunger is connected to the other end of a plunger energized by a spring in the direction for increasing the volume of the pump room. SOLUTION: In drive means 221 , 222 , plural piezo electric elements are piled along the axial line direction of a plunger 42 and also the other end of the piezo electric element piled body 62 whose one end is connected to the other end of the plunger 42 is supported to a support member 59 staying on a fixed position for a pump housing 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the other end of a plunger which has one end facing the pump chamber and is slidably fitted to the pump housing and which is spring-biased in a direction to increase the volume of the pump chamber. , A plunger pump to which drive means for applying a pressing force to the plunger in a direction of reducing the volume of the pump chamber is connected.

[0002]

2. Description of the Related Art Conventionally, such a plunger is already known, for example, from Japanese Patent Application Laid-Open No. 7-47938.

[0003]

In the conventional plunger pump described above, the driving means for reciprocating the plunger is composed of an electric motor and a cam provided on the output shaft of the motor, and is slidably contacted with the cam. Since the plunger is reciprocally driven in the axial direction by the rotational movement of the cam, it is inevitable that the plunger becomes large and heavy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a plunger pump which can be reduced in weight and size.

[0005]

In order to achieve the above object, the present invention is directed to a direction in which one end of a pump chamber is slidably fitted to the pump chamber and the volume of the pump chamber is increased. In a plunger pump in which a drive means for applying a pressing force in a direction of reducing the volume of the pump chamber is connected to the other end of the spring-biased plunger, the drive means is arranged along the axial direction of the plunger. A plurality of piezoelectric elements are stacked, and one end of which is connected to the other end of the plunger, and the other end of which is supported by a support member that is in a fixed position with respect to the pump housing. And

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the accompanying drawings.

1 and 2 show an embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a vehicle anti-lock brake control device to which the present invention is applied, and FIG. 2 is a longitudinal section of a plunger pump. It is a figure.

First, in FIG. 1, a tandem type master cylinder M is provided with a pair of output ports 13a and 13b for outputting a braking fluid pressure according to the depression of a brake pedal P, and a left front wheel brake B _FL and a right wheel brake B _FL . A proportional pressure reducing valve 14 _R connected to the rear wheel wheel brake B _RR , a right front wheel wheel brake B _FR , and a proportional pressure reducing valve 14 _L connected to the left rear wheel wheel brake B _RL , and the both output ports 13a. , 1
3b and the vehicle anti-lock brake control device 1
5 is installed.

This anti-lock brake control device 15
Is the wheel brake B for the left front wheel_FL, Wheel brake for right rear wheel
B_RR, Wheel brake B for the right front wheel_FRAnd left rear wheel
Rake B_RL4 normally open solenoid valves that individually correspond to
V_OFL, V_ORR, V_OFR, V_ORLAnd each normally open solenoid valve V
_OFL~ V_ORL4 checkers connected in parallel to
Ku valve 17_FL, 17_RR, 17_FR, 17_RLAnd each wheel
Rake B_FL~ B_RL4 normally closed solenoid valves individually compatible with
V_CFL, V_CRR, V_CFR, V_CRLAnd the wheel shake for the left front wheel
B_FLAnd wheel brake B for the right rear wheel_RRSide and right
Front wheel brake B_FRAnd wheel brake B for the left rear wheel
_RLA pair of reservoirs 19 individually corresponding to the sides₁,
19_TwoAnd both reservoirs 19₁, 19_TwoIntake valve 20₁,
20_TwoIndividual drive means 22 connected via
₁, 22_TwoPlunger pump 21 having₁, 2
1_TwoAnd both plunger pumps 21₁, 21_TwoDischarge valve 2
Three₁, 23 _TwoA pair of damper chambers 2 connected via
4₁, 24_TwoAnd the output port 1 of the master cylinder M
3a, 13b and the plunger pump 21₁, 21
_TwoOrifices 25 that are respectively interposed between₁, 25_TwoWhen
Each normally open solenoid valve V_OFL~ V_ORLAnd each normally closed type
Solenoid valve V_CFL~ V_CRLDemagnetization / excitation of electronic control unit
Switching control is performed by 26.

Normally open solenoid valve V_OFLIs the master cylinder M
One output port 13a and the wheel brake B for the left front wheel_FL
And a normally open solenoid valve V_ORRIs the output port
Wheel 13a and wheel brake B for the right rear wheel_RRRatio connected to
Example Pressure reducing valve 14_RAnd a normally open solenoid valve V_OFR
Is the other output port 13b of the master cylinder M and the front right
Wheel brake B for wheels_FRNormally open solenoid valve installed between
V_ORLIs the output port 13b and the wheel breaker for the left rear wheel.
B_RLProportional pressure reducing valve 14 connected to_LIs installed between
You. Check valve 17_FL~ 17_RLIs the corresponding wheel
Rake B_FL~ B _RLAllows only the flow of hydraulic fluid from
Each normally open solenoid valve V_OFL~ V_ORLConnected in parallel to
It is.

The normally closed solenoid valve V _CFL is provided between the wheel brake B _FL for the left front wheel and the reservoir 19 ₁ and is a normally closed solenoid valve V _CRR.
Is between the proportional pressure reducing valve 14 _R and the reservoir 19 ₁ , the normally closed solenoid valve V _CFR is between the front wheel brake B _FR and the reservoir 19 ₂ , and the normally closed solenoid valve V _CRL is the proportional pressure reducing valve 1.
4 _L and the reservoir 19 ₂ , respectively.

Such anti-lock brake control device
According to No. 15, there is a possibility that each wheel will not lock.
When normally braking, each normally open solenoid valve V_OFL~ V_ORLDisappears
The valve is open in the magnetic state, and each normally closed solenoid valve V
_CFL~ V_CRLIs demagnetized and is closed. But
Output from one output port 13a of the master cylinder M
The braking fluid pressure applied is the normally open solenoid valve V_OFLLeft front through
Wheel brake B for wheels_FLNormally open solenoid valve
V_ORRAnd proportional pressure reducing valve 14_RFor the right rear wheel
Rake B_RRTo the other side of the master cylinder M
The braking fluid pressure output from the force port 13b is the normally open electromagnetic pressure.
Valve V_OFRWheel brake B for the right front wheel via _FRAct on
With normally open solenoid valve V_ORLAnd proportional pressure reducing valve 14_LTo
Via the wheel brake B for the left rear wheel_RLAct on.

At the time of anti-lock control when the wheel is about to enter the locked state during braking, the normally open solenoid valve corresponding to the wheel that is about to enter the locked state among the _normally open solenoid valves V _{OFL to} V _ORL. Is excited to close the valve, and at the same time, of the normally closed solenoid valves V _{CFL to} V _CRL , the normally closed solenoid valves corresponding to the wheels are excited and opened. Then, a part of the brake fluid pressure is released to the reservoir 19 ₁ or 19 ₂ and reduced. When the brake fluid pressure is maintained, the normally open solenoid valves V _{OFL to} V _ORL are excited to close the valve, and the normally closed solenoid valves V _{CFL to} V _CRL are demagnetized to maintain the closed state. Of course, when increasing the braking fluid pressure, deenergize the normally open solenoid valves V _{OFL to} V _ORL and open them, and demagnetize the normally closed solenoid valves V _{CFL to} V _CRL to keep them closed. Good.

Thus, the pair of plunger pumps 21 ₁ , 2
Reference numeral 1 ₂ is an element that is operated during the antilock control, and the hydraulic fluid released to the reservoirs 19 ₁ and 19 ₂ flows from the plunger pumps 21 ₁ and 21 ₂ to the damper chamber 2.
It is returned to the upstream side of each of the normally open solenoid valves V _{OFL to} V _ORL via 4 ₁ , 24 ₂ and orifices 25 ₁ , 25 ₂ . Therefore, the depression amount of the brake pedal P in the master cylinder M does not increase by the amount released to the reservoirs 19 ₁ and 19 ₂ , and the plunger pumps 21 ₁ and 21 2
The pulsation of the hydraulic fluid sent from ₂ is the damper chamber 24 ₁ , 24
₂ and the orifices 25 ₁ and 25 ₂ are damped, and the pulsation is not transmitted to the brake pedal P.

Whether the wheels are likely to enter the locked state in the electronic control unit 26 which controls the demagnetization / excitation of the normally open solenoid valves V _{OFL to} V _ORL and the normally closed solenoid valves V _{CFL to} V _CRL . Wheel speed sensors 27 _FL , 27 _RR , 27 _FR , which individually detect the wheel speed of each wheel in order to judge whether
27 _RL detection signal is input, and a detection signal of a handbrake detection sensor 29 that detects whether or not the handbrake lever 28 is operated is also input. Further, when in the antilock control state, the electronic control unit 26
An alarm 30 such as a lamp activated by is connected to the electronic control unit 26.

In FIG. 2, the antilock brake control device 15 is provided with a metal base 34 which is formed in a block shape and is mounted on a vehicle body.
Four _normally open solenoid valves V _OFL , V _ORR , V _OFR , V _ORL ,
Four normally closed solenoid valves V _CFL , V _CRR , V _CFR and V _CRL ,
Four check valves 17 _FL , 17 _RR , 17 _FR , 17 _RL , a pair of reservoirs 19 ₁ , 19 ₂ , a pair of intake valves 20 ₁ , 2
0 ₂ , a pair of plunger pumps 21 ₁ , 21 ₂ , a pair of discharge valves 23 ₁ , 23 ₂ , a pair of damper chambers 24 ₁ , 2
4 ₂ and a pair of orifices 25 ₁ and 25 ₂ are provided.

The plunger pump 21 ₁ uses the base body 34 as a pump housing. The base body 34 is provided with a mounting hole 35 having one end open to one surface 34a thereof and a step portion 36 facing the one surface 34a side of the base body 34. A sliding hole 37 coaxially connected to the other end of the mounting hole 35 is bored therethrough.

The mounting hole 35 has a first fitting hole 38 and a first fitting hole 38, one end of which is opened at one surface 34a of the base 34.
And a second fitting hole portion 39 having one end coaxially connected to the other end of the first fitting hole portion 38.
A step portion 36 is formed on the base body 34 so as to be sandwiched between the fitting hole portion 39 and the sliding hole 37, and faces the one end side of the mounting hole 35 between the first and second fitting hole portions 38, 39. Step 40
Is provided.

A plunger 42 is fitted in the sliding hole 37 so as to be able to reciprocate in the axial direction, and the sliding hole 37 is provided at two locations on the outer periphery of the plunger 42 which are spaced apart in the axial direction. Annular seal members 43 and 44 that are in sliding contact with the inner surface are mounted. Thus, the base 3 is provided between the seal members 43 and 44.
4 and the plunger 42, an annular suction chamber 45 is formed, and the suction chamber 45 is provided in the base body 34.
It is connected via 6 to the reservoir 19 ₁ (see FIG. 1).

A dish-shaped cap 47 is liquid-tightly fitted to one end side of the mounting hole 35, that is, the first fitting hole portion 38, and engages with the outer peripheral edge of the cap 47 to mount the cap 47. A retaining ring 48 for preventing the detachment from the 35 is fitted to the inner surface of the first fitting hole portion 38. A plug 49 is press-fitted into the other end of the mounting hole 35, that is, the second fitting hole 39. The plug 49 has a large diameter portion 49a having a smaller diameter than the first fitting hole portion 38 but a larger diameter than the second fitting hole portion 39, and a small diameter portion 49b fitted into the second fitting hole portion 39. The small diameter portion 49b and the large diameter portion 49a are arranged coaxially in series.
An annular recess 49c is provided on the outer surface of the side wall. When the plug 49 is pressed toward the sliding hole 37 so that the small diameter portion 49b of the plug 49 is fitted into the second fitting hole portion 39, the inner peripheral portion of the stepped portion 36 forms the annular recess 49c. The plug 49 is fixed to the base 34 by being plastically deformed so as to be filled and caulked. Plug 49 and plunger 42
A pump chamber 50 is formed therebetween, and the plunger 42 is slidably fitted in the sliding hole 37 with one end thereof facing the pump chamber 50. A discharge chamber 51 is formed between the plug 49 and the cap 47, and the base 34 communicates with the discharge chamber 51, and the discharge port 13a of the master cylinder M (see FIG. 1) and the normally open solenoid valves V _OFL , V _ORR ( A discharge passage 52 connected to (see FIG. 1) is provided.

A return spring 53 is contracted between the plug 49 and the plunger 42 in the pump chamber 50, and
2 is urged by the return spring 53 in the direction in which the other end projects from the sliding hole 37.

The plunger 42 has a suction hole 5 which is in constant communication with the suction chamber 45 via a filter 54 mounted on the outer circumference of the plunger 42 and is capable of communicating with the pump chamber 50.
5, a suction valve 2 for coaxially opening and closing a suction hole 55 in the pump chamber 50 according to the pressure reduction and pressure increase of the pump chamber 50.
0 ₁ is stored and arranged. Further, the plug 49 is provided with a discharge hole 56 which communicates with the pump chamber 50 and can communicate with the discharge chamber 51.
The discharge valve 23 that opens and closes the discharge hole 56 according to increase / decrease of 0
₁ is stored and arranged.

The base 34 has a bottomed fitting hole 57 for opening the other end of the sliding hole 37 on the side surface, and the axis of the fitting hole 57 is a sliding hole 37.
Is provided so as to be orthogonal to the axis line of the fitting hole 57.
A plurality of positioning holes 58, 58 ... Are provided at positions closed from the center of the closed end. A disk-shaped support member 59 having a plurality of positioning pins 60, 60, which fit into the positioning holes 58, 58, respectively, is fitted in the fitting hole 57, and the support member 59 is provided outside the support member 59. A retaining ring 61 that engages with the peripheral edge is fitted into the inner surface of the fitting hole 57. That is, the support member 59 is fixed to the base body 34.

Driving means 2 for this plunger pump 21 _1.
2 _1, the plunger 42 is urged in a direction to increase the volume of the pump chamber 50 by the spring force of the spring 53 return,
This is for applying a pressing force in the direction of reducing the volume of the pump chamber 50 against the spring force of the return spring 53, and is formed by laminating a plurality of piezoelectric elements along the axial direction of the plunger 42. The body 62 is provided on the support member 59. Thus, the support member 59 is provided with a support hole 63 which is coaxial with the slide hole 37 and whose inner end is closed, and a slide plate 64 which contacts the other end of the plunger 42 slides in the support hole 63. The piezoelectric element laminate 62, which is movably fitted and has one end abutting against the sliding plate 64, is housed in the support hole 63 such that the other end is supported by the inner end blocking portion of the support hole 64. It

By the way, the driving means 22_TwoPlan with
Japump 21_TwoIs the plastic with respect to the axis of the support member 59.
Nja pump 21₁And the symmetrical position, the plunger pump
21 ₁Having the same configuration as that of the base 34
And the plunger pump 21_TwoThe main components of
Plunger pump 21₁Description of the same reference numerals as
The detailed description will be omitted only with reference numerals.

Thus, in the piezoelectric element laminates 62, 62 of both the driving means 22 ₁ , 22 ₂ , the currents boosted by the boosters 65 ₁ , 65 ₂ controlled by the electronic control unit 26 are cyclical. Is supplied to. At this time, the application of current to both the piezoelectric element laminates 62, 62 may be alternately repeated if necessary.

Both piezoelectric element laminates 62, 62 drive the plungers 42, 42 in a direction in which they expand in the axial direction when the current is applied to reduce the volume of the pump chamber 50, and when the current is not applied, the return springs 53, 53. Is reduced in the axial direction by the spring force acting on the plungers 42, 42.

Next, the operation of this embodiment will be described. In the plunger pumps 21 ₁ and 21 ₂ , when a current is applied to the piezoelectric element laminates 62 and 62, the piezoelectric element laminates 62 and 62 expand in the axial direction. , Plunger 42, 4
2 is made to exert a pressing force in the direction of reducing the volume of the pump chambers 50, 50, and when no current is applied to the piezoelectric element laminates 62, 62, the return springs 53, 53 cause the plunger 4 to move.
The spring force acting on 2, 42 causes axial contraction.
As the plungers 42, 42 are axially reciprocally driven in this manner, the plunger pumps 21 ₁ , 21 ₂ are operated.

Thus, the driving means 22 ₁ and 22 ₂ are the support members in which the piezoelectric element laminates 62 and 62 formed by laminating a plurality of piezoelectric elements along the axial direction of the plungers 42 and 42 are fixed to the base 34. As compared with the conventional plunger pump in which the motor is mounted on the base body 34 by being supported by 59, the driving means 22 ₁ ,
22 _{2 and then the} plunger pumps 21 ₁ and 21 ₂ can be downsized, and the weight can be reduced.

Although the embodiments of the present invention have been described in detail, 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 appended claims. It is possible to do.

For example, the present invention is not limited to the one for the vehicle anti-lock brake control device 15, but can be widely applied to a plunger pump in which a plunger having one end facing the pump chamber is axially reciprocally operated. is there.

[0032]

As described above, according to the present invention, the driving means is formed by laminating a plurality of piezoelectric elements along the axial direction of the plunger, and one end of which is connected to the other end of the plunger. Since the other end is supported by a support member that is in a fixed position with respect to the pump housing, the size and weight of the plunger pump can be reduced as compared with a conventional plunger pump that uses a motor.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a vehicle anti-lock brake control device to which the present invention is applied.

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

[Explanation of reference numerals] 21 ₁ , 21 ₂ ... Plunger pump 22 ₁ , 22 ₂ ... Driving means 34 ... Base body as pump housing 42 ... Plunger 50 ... Pump chamber 59 ... Support Member 62 ... Piezoelectric element laminate

Claims (1)

[Claims] 1. A plunger (1), one end of which faces a pump chamber (50), is slidably fitted in a pump housing (34) and is spring-biased in a direction to increase the volume of the pump chamber (50). 42) to the other end of the pump chamber (50)
The pressing force in the direction of reducing the volume of the plunger (4
In the plunger pump driving means (22 _1, 22 ₂₎ is connected to provide a 2), drive means (22 _1, 2
2 ₂ ) is formed by stacking a plurality of piezoelectric elements along the axial direction of the plunger (42), and has one end connected to the other end of the plunger (42) and the other end of the piezoelectric element stack (62). A plunger pump, which is supported by a support member (59) in a fixed position with respect to the pump housing (34).