JPH0575035U - Hydraulic circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] In a hydraulic circuit provided with pressure supply means for supplying hydraulic pressure with a phase difference to mutually independent first and second systems, operation discharged from the pressure supply means To reduce the pulsation of liquid with a simple structure. [Structure] The first and second sides on the discharge side of the pressure supply means
A communication part is provided to connect and connect the systems. First and second connecting portions are divided by an elastic structure so that the first and second hydraulic fluids are not mixed with each other and are connected to the first and second systems, respectively.
Form a damping chamber. The elastic structure is a spherical body made of an elastic material such as rubber, and is slidably fitted in the communication portion in a liquid-tight state. Positioning springs are arranged in the first and second damping chambers, and when the hydraulic pressures in the first and second damping chambers are substantially balanced at low pressure, the elastic structure is located near the center of the communicating portion in the length direction. To be located.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic circuit, and more particularly, to a hydraulic circuit having a pressure supply means for supplying a hydraulic pressure with a phase difference to a first system and a second system which are independent of each other. The pulsation of the hydraulic fluid is smoothed and reduced by a simple structure, and is particularly preferably applied to an antilock brake system.

[0002]

[Prior Art]

 Conventionally, in a hydraulic circuit having two independent systems to which hydraulic pressure is supplied from the pressure supply means with a phase difference, only the pressure of the operating fluid between these two systems is kept while the hydraulic fluid is kept independent. Is transmitted to each other to smooth the pulsation of the hydraulic fluid discharged by the pressure supply means, thereby lowering the peak value of the pressure of the hydraulic fluid.

For example, Japanese Laid-Open Patent Publication No. 1-254459 proposes a hydraulic circuit as shown in FIG. This hydraulic circuit constitutes an anti-lock brake system (hereinafter abbreviated as "ABS"), and includes a first system 3 connecting the master cylinder 1 and the wheel cylinders 2A and 2B, a master cylinder 1 and a wheel cylinder 2C. , And a second system 4 for connecting 2D. The first and second pump sections 5A and 5B of the pressure supply means 6 are interposed on the reflux side of the first and second systems 3 and 4, respectively. This pressure supply means 6 is an opposed type plunger pump that drives the first and second pump parts 5A and 5B by one motor 7, and the first and second pump parts 5A and 5B are used to form the first and second system 3 The hydraulic pressures are supplied to 4 and 4, respectively.

A damping means 8 as shown in detail in FIG. 7 is interposed between the master cylinder 1 and the discharge sides of the first and second pump parts 5 A and 5 B. The damping means 8 is provided with an inner hole 8a connected to the discharge side of the first and second pump parts 5A and 5B. A floating piston 9 is slidably fitted in the inner hole 8a in a liquid-tight state to form first and second damping chambers 10A and 10B. The first and second damping chambers 10A and 10B are connected to the master cylinder 1 via an orifice 12 and a check valve 13, respectively.

In the above hydraulic circuit, for example, when the first pump portion 5A is in the discharge stroke and the second pump 5B is in the suction stroke, the pressure difference between the first and second damping chambers 10A and 10B causes The floating piston 9 moves to the side of the second damping chamber 10B, the pulse pressure of the first pump portion 5A is transmitted to the second pressure reducing chamber 10B via the floating piston 9, and the first pump portion 5A discharges it. The hydraulic fluid pressure is apparently transmitted to the second decompression chamber 10B. Such operation is repeated every half cycle of the operation of the first and second pump parts 5A and 5B. Therefore, in the above hydraulic circuit, it is possible to smooth the pulsation of the hydraulic fluid discharged from the first and second pump parts 5A and 5B and reduce the pulsation width, thereby reducing the operating noise of the ABS.

[0006]

[Problems to be solved by the device]

 In the damping means 8, the floating piston 9 is moved to transmit the hydraulic pressure of one system to the other system. The floating piston 9 is fluid-tightly slidable in the inner hole 8a. In order to fit it to the floating piston 9, the floating piston 9 itself is provided with a pair of lands 9a and 9b, and the 0-ring 15 sandwiched by the pair of backup rings 14A and 14B is provided in the space between the lands 9a and 9b. It is configured to be placed. Further, in the damping means 8, it is necessary to arrange the springs 16A, 16B in the first and second damping chambers 10A, 10B so that the floating piston 9 is located near the center of the inner hole 8a. That is, in the conventional hydraulic circuit of this type, the structure of the damping means is complicated and the number of parts is large, so that it is not suitable for mass production and the manufacturing cost is high.

An object of the present invention is to solve the conventional problems as described above, smooth the pulsation of the working fluid discharged from the pressure supply means, and reduce the peak value of the working fluid pressure with a simple structure. It was done.

[0008]

[Means for Solving the Problems]

 Therefore, the present invention is a hydraulic circuit having first and second systems independent of each other, and provided with pressure supply means for supplying hydraulic pressure with a phase difference to each system. A communication part is provided on the discharge side of the supply means for communicating the first and second systems, and the communication part is partitioned by the elastic structure so as not to mix the working fluid, and the first and second systems are respectively connected. And a second damping chamber, which provides a hydraulic circuit.

The elastic structure is composed of, for example, an elastic plug member in which a spherical body made of an elastic material such as rubber, a cylindrical rounded body or the like is slidably fitted in the communication portion in a liquid-tight state. In this case, it is preferable to arrange a positioning spring in the first and second damping chambers.

Further, the elastic structure may be a diaphragm fixed so as to partition the vicinity of the center of the communication portion. In this case, it is preferable that a portion of the communication portion where the diaphragm is arranged is a diameter-enlarged portion having an enlarged cross-sectional area.

In the hydraulic circuit of the present invention, the first and second damping vessels are connected to the discharge sides of the pressure supply means of the first and second systems, respectively, and the first and second damping vessels are connected by the communicating portion. It is preferable that the container is in communication with each other.

Further, the hydraulic circuit of the present invention is preferably applied to ABS. In this case, the first and second systems are connected to the main flow path connecting the master cylinder and the wheel cylinder via the supply valve, and the main cylinder side branched from the main flow path via the discharge valve and the pressure supply means. The first and second systems may be connected to each other by a communication section between the pressure supply means and the master cylinder.

[0013]

Since the hydraulic circuit according to the present invention is configured as described above, when the pressure of the hydraulic fluid of one system is higher than the pressure of the hydraulic fluid of the other system on the discharge side of the pressure supply means. The elastic structure provided in the communication part moves or deforms according to the pressure difference, and the volume of the high-pressure side damping chamber increases, while the volume of the low-pressure side damping chamber decreases and the high-pressure side system The pressure of the working fluid is transmitted to the system on the low pressure side, the pulsation of the working fluid discharged by the pressure supply means is smoothed, and the peak value of the pressure of the working fluid is reduced.

For example, when an elastic plug member such as a spherical body or a cylindrical rounded body is adopted as the elastic structure, they are liquid-tight and have a low pressure depending on the pressure difference between the first and second damping chambers. Slide to the damping chamber side. On the other hand, when a diaphragm is used as the elastic structure, the diaphragm expands toward the low pressure side according to the pressure difference.

Further, when the damping vessels are connected to the first and second systems as described above, the volume of the damping chamber is increased by the amount of the damping vessel provided, and the smoothing of the pulsation and the peak value of pressure Reduction is more efficient.

Furthermore, when the hydraulic circuit of the present invention is applied to an ABS, smoothing the pressure pulsation of the hydraulic fluid in the first and second systems as described above enables the anti-lock control. Noise is reduced and pulsation transmission to the brake pedal is suppressed.

[0017]

【Example】

 Next, the present invention will be described in detail based on the embodiments shown in the drawings. As shown in FIG. 1, the hydraulic circuit according to the first embodiment of the present invention is an X pipe type anti-lock brake system (hereinafter abbreviated as "ABS") having two hydraulic circuits. A first system 23 connecting the master cylinder 21 to the wheel cylinders 22A, 22B for the right front wheel and the left rear wheel, and a second system 24 connecting the master cylinder 21 to the wheel cylinders 22C, 22D for the left front wheel and the right rear wheel Is equipped with.

The first system 23 includes three-port two-position control type flow rate control valves 25A and 25B that form supply valves between the master cylinder 21 and the right front wheel and left rear wheel wheel cylinders 22A and 22B, respectively. The main flow path and the flow control valves 25A, 25B are provided with normally closed discharge valves 26A, 26B, which are electromagnetic valves, and the discharge ports of the discharge valves 26A, 26B are connected via the pressure supply means 27 to the master cylinder. It is equipped with a return path that connects to 21. Further, in the first system 23, the reservoir 28A is arranged between the discharge valves 26A, 26B and the pressure supply means 27.

In the second system 24, the wheel cylinders 22C and 22D for the left front and right rear wheels, the discharge valves 26C and 26D, and the reservoir 28B are connected to the master cylinder 1 in the same configuration as the first hydraulic circuit 23. There is.

In the pressure supply means 27, as shown in FIG. 2, the first and second plungers 34A and 34B are arranged 180 degrees facing each other with the eccentric cam 33 mounted on the rotary shaft 32 of the motor 31 being sandwiched therebetween. As shown in FIG. 1, the opposed plunger pump includes a first pump portion 35A on the side of the first plunger 34A in the first system 23 and a second pump portion 35B on the side of the second plunger 34B. It is interposed in the second system 24.

As shown in FIG. 2, the first and second pump parts 35A and 35B are slidably fitted to the plunger case 36 with the first and second plungers 34A and 34B, respectively. The second plungers 35A and 35B are elastically brought into contact with the eccentric cam 33 by the repulsive force of a return spring 37 that is compressed between the second plunger 35A and 35B.

Further, in the first and second pump parts 35 A and 35 B, from the suction port 39 provided in the plunger case 36, the liquid passage 40 provided in the first and second plungers 34 A and 34 B, the spring chamber 41, and the plunger. A flow path communicating with a discharge port 44 provided in the plunger plug 42 through a liquid chamber 43 provided between the case 36 and the plunger plug 42 is formed, and the liquid passage 40 and the opening of the plunger case 42 are formed. Are provided with ball valves 46A and 46B. Further, in the first pump portion 35A and the second pump portion 35B, the suction port 39 is connected to the reservoir 28, while the discharge port 44 is connected to the master cylinder 21.

A damping means 50 is interposed between the discharge side of the pressure supply means 27 and the master cylinder 21. The damping means 50 is provided with a communication part 51 which connects the first and second systems 23 and 24 to communicate with each other on the discharge side of the pressure supply means 27, and the elastic structure 53 is arranged in the communication part 51. ..

As shown in FIG. 2, the communicating portion 51 is formed by liquid-tightly sealing the openings at both ends of the circular pipe member with the plugs 55A and 55B fixed to the housing 54, and the first and second systems are provided at both end portions, respectively. A connection portion 56 for connecting to 23 and 24 is provided.

The elastic structure 53 of the first embodiment is a spherical member made of an elastic material such as rubber that constitutes the elastic plug member. Further, the diameter of the elastic structure 53 is set to be substantially equal to the inner diameter of the communicating portion 51. In the first embodiment, the elastic structure 53 as described above is slidably fitted in the vicinity of the center of the communication part 51 in a liquid-tight manner so as to partition the communication part 51 into two chambers, and the first system 23 The side is the first damping chamber 58A, and the second system 24 side is the second damping chamber 58B.

Positioning springs 59A and 59B are arranged in the first and second damping chambers 58A and 58B, respectively. The positioning springs 59A and 59B have one end fixed to the plugs 55A and 55B side, and the other end positioned near the center of the communication portion 51 in the longitudinal direction. Therefore, in the first embodiment, the elastic structure 53 is pushed back by the positioning springs 59A and 59B in a state where the pressures in the first and second damping chambers 58A and 58B are substantially balanced at low pressure. Located in the central portion of 51, the first and second damping chambers 58A and 58B have the same volume.

As described above, in the first embodiment, the first and second damping chambers 58A and 58B are provided by inserting the elastic structure 53 into the communication portion 51, and the first and second damping chambers 58A and 58B are provided. The number of parts required to configure the two damping chambers 58A and 58B is small, and the structure is simple.

Damping capacitors 61A and 61B are connected to the plugs 55A and 55B of the first and second damping chambers 58A and 58B, respectively. The damping vessels 61A and 61B are made of rigid bodies, and their cross-sectional areas are set to be larger than those of the conduits and the communication section 51 that form the first and second systems 23 and 24. In the first embodiment, by connecting the first and second damping chambers 61A and 61B to the first and second damping chambers 58A and 58B as described above, the first and second damping chambers 58A and 58B are connected. The volume is increasing.

Further, in the pressure reducing means 50 of the first embodiment, between the master cylinder 21 and the connection portion 56 between the first and second damping chambers 58 A and 58 B and the first and second systems 23 and 24. The first and second orifice means 63A and 63B are respectively interposed between the two.

Next, the operational features of the first embodiment having the above configuration will be described. During the non-antilock control, the hydraulic pressure of the master cylinder 21 is supplied to the wheel cylinders 22A to 22D via the flow rate control valves 25A to 25D according to the depression amount of the brake pedal 62. When the antilock control is started, the motor 31 is driven and the pressure supply means 27 starts operating. At the time of antilock depressurization, the discharge valves 26A to 26D are opened, and the hydraulic fluid discharged from the discharge valves 26A to 26D is circulated to the master cylinder 21 side by the pressure supply means 27.

As described above, in the pressure supply means 27 composed of the plunger type pump, the first and second plungers 34 A and 34 B reciprocate in the plunger case 36 in accordance with the rotation of the rotary shaft 32 of the motor 31, and the suction is performed. The hydraulic fluid sucked from the port 39 is discharged from the discharge port 44.

The pressure of the hydraulic fluid discharged from the first and second pump portions 35A and 35B is the positive region of the sine wave as shown by the solid line in FIGS. 3 (A) and 3 (B), respectively. Pulsates with a waveform similar to the one that was taken out. Further, in the first embodiment, since the plungers 34A, 34B of the first and second pump parts 35A, 35B are arranged 180 ° opposite to each other, the discharge operation of the first and second pump parts 35A, 35B is performed. The pressure characteristic of the liquid has a phase difference of half the period T.

The hydraulic pressures of the hydraulic fluid discharged from the first and second pump portions 35A and 35B act on the first and second damping chambers 58A and 58B of the damping means 50, respectively. For example, in the above-described FIGS. 3A and 3B, during the period from time t = 0 to t = 1 / 2T 2, the first pump portion 35A is in the discharge stroke and the discharge hydraulic pressure increases, while The pump portion 35B is in the suction stroke and the discharge hydraulic pressure is substantially constant, and this hydraulic pressure acts on the first and second damping chambers 58A and 58B, respectively. Therefore, the hydraulic pressure in the first damping chamber 58A becomes larger than the hydraulic pressure in the second damping chamber 58B, and the elastic structure 53 moves to the second damping chamber 58B side according to this pressure difference, While the volume of 58A increases, the volume of the second attenuation chamber 58B decreases. Due to the movement of the elastic structure 53, the pulsation of the hydraulic fluid on the first system 23 side is transmitted to the second system 24, and the amount of hydraulic fluid discharged from the first pump portion 35A is apparently on the second system 24 side. Transmitted.

Since the above operation is repeated every half cycle, as shown by the dotted lines in FIGS. 3A and 3B, respectively, the first and second pump portions 35A and 35B are connected to the damping means 50. The pulsation of the hydraulic fluid discharged to the master cylinder 21 side through is smoothed. Further, the pulsation width ΔP of the discharge hydraulic pressure is about half of the pulsation width ΔP ′ in the case where the damping means 50 is not provided, as shown by the alternate long and short dash line in FIGS. 3 (A) and 3 (B). The peak value of hydraulic fluid pressure is reduced. In the first embodiment, the first and second damping vessels 61A and 61B are provided to increase the volumes of the first and second attenuation chambers 58A and 58B, so that the pulsation of the working fluid as described above is smoothed. And pulsation width can be efficiently reduced.

Therefore, in the present embodiment, the generation of vibration and noise due to the pulsation of the hydraulic fluid discharged from the pressure supply means 27 is suppressed, and this pulsation is transmitted to the brake pedal 62, which gives the driver discomfort. Can be suppressed.

FIG. 4 shows a second embodiment of the present invention. In the second embodiment, the elastic structure 65 is made of an elastic material such as rubber and has an outer diameter set to be substantially equal to the inner diameter of the communicating portion 51, that is, a bottom surface and a side surface of a cylindrical body. The connecting portion has a curved shape, and the elastic structure 65 is slidably fitted in the communicating portion 51 in a liquid-tight state as in the first embodiment. Since the other structure and operation of the second embodiment are the same as those of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

FIG. 5 shows a third embodiment of the present invention. In the third embodiment, an elastic structure 67 made of a diaphragm is provided at the center of the communication part 51. In the third embodiment, a diameter-enlarged portion 68 having a large cross-sectional area is provided in the central portion of the communication portion 51 in the length direction, and the center portion of the diameter-enlarged portion 68 covers the entire inner cross section of the diameter-enlarged portion 68. An elastic structure 67 made of a diaphragm is fixed to the. In the third embodiment, for example, when the hydraulic pressure in the first damping chamber 58A is higher than the hydraulic pressure in the second damping chamber 58B, the elastic structure 67 elastically moves toward the second damping chamber 58B side according to the pressure difference. And the pulsation of the hydraulic fluid discharged by the pressure supply means 27 can be smoothed.

In the third embodiment, since the elastic structure 67 is composed of the diaphragm fixed to the expanded diameter portion 68 as described above, the positioning spring 59A which is necessary in the first and second embodiments. , 59B are unnecessary, the number of parts can be further reduced, and the structure of the pressure reducing means 27 can be simplified. Further, in the third embodiment, as described above, since the elastic structure 67 composed of the diaphragm is provided in the enlarged diameter portion 68 having the enlarged cross-sectional area, the discharge of the first and second pump portions 35A, 35B is performed. Even when the hydraulic pressure difference is large, the pulsation of one system can be transmitted to the other system by a slight expansion deformation of the elastic structure 67.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, although the hydraulic circuit of the above embodiment constitutes the ABS, the present invention can be applied to other hydraulic circuits. Further, in the first and second embodiments, a spherical body or a rounded cylindrical body is used as the elastic plug member that constitutes the elastic structure, but this elastic plug member can be slid in the liquid tight state of the communicating portion. Any shape may be used as long as it can be inserted.

[0040]

[Effect of the device]

 As is clear from the above description, in the hydraulic circuit according to the present invention, the elastic structure composed of the spherical body and the cylindrical rounded body is provided in the liquid tight state of the first and second systems on the discharge side of the pressure supply means. Since the first and second damping chambers are provided in the communication part as a structure to be slidably fitted in, when the pressure in one damping chamber becomes higher than the pressure in the other damping chamber, this The elastic structure moves according to the pressure difference to increase or decrease the volume of the damping chamber, so that the pulse pressure of the hydraulic fluid of one system can be transmitted to the other system, and the operation that the pressure supply means discharges. It is possible to smooth the pulsation of the liquid, reduce the pulsation width, and reduce the peak value of the pressure of the hydraulic fluid.

In particular, according to the present invention, the elastic plug member is slidably fitted in a fluid-tight state in the communication portions provided in the first and second systems as described above, so that With the extremely simple structure of forming the damping chamber, smoothing of the pulsation of the hydraulic fluid as described above can be achieved, and the number of parts can be reduced. Therefore, the hydraulic circuit of the present invention is suitable for mass production and can reduce the manufacturing cost.

Further, when the diaphragm is fixed to the communication part as the elastic structure, a component for forming the damping chamber in the communication part is not necessary other than this diaphragm, and the number of parts is further reduced. It is possible to simplify.

When the first and second damping chambers are connected to the first and second damping chambers, the volumes of the first and second damping chambers can be increased, so that the pulsation of the pressure of the hydraulic fluid is increased. Can be smoothed more efficiently.

Further, when the present invention is applied to the ABS, the pulsation of the hydraulic fluid can be smoothed and reduced as described above, so that the generation of vibration and noise due to the pulsation during antilock control can be suppressed. It is possible to prevent this pulsation from being transmitted to the brake pedal.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of main parts showing a first embodiment.

3A and 3B are diagrams showing the hydraulic characteristics of the first embodiment.

FIG. 4 is a cross-sectional view of an essential part showing a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of an essential part showing a third embodiment of the present invention.

FIG. 6 is a schematic view showing a conventional example.

7 is a schematic sectional view showing the damping means of FIG.

[Explanation of symbols]

 21 master cylinder 22 wheel cylinder 23 first system 24 second system 25 flow control valve 26 discharge valve 27 pressure supply means 50 damping means 51 communicating portion 53,65,67 elastic structure 55 plug 58 damping chamber 59 positioning spring 61 auxiliary damping Chamber 68 Expanding part

Claims (5)

[Scope of utility model registration request] 1. A hydraulic circuit, comprising first and second systems independent of each other, and provided with pressure supply means for supplying hydraulic pressure with a phase difference to each system, said pressure supply means A communication part that connects the first and second systems is provided on the discharge side of the first and second communication systems, and the communication part is partitioned by the elastic structure so as not to mix the hydraulic fluid, and the first and second systems communicate with the first and second systems, respectively. A hydraulic circuit characterized by forming a damping chamber. 2. The hydraulic circuit according to claim 1, wherein the elastic structure comprises an elastic plug member slidably fitted in the communication portion in a liquid-tight state. 3. The hydraulic circuit according to claim 1, wherein the elastic structure comprises a diaphragm fixed so as to partition the vicinity of the center of the communication portion. 4. The first and second damping vessels are connected to the discharge sides of the pressure supply means of the first and second systems, respectively, and the first and second damping vessels are connected by the communicating portion. The hydraulic circuit according to any one of claims 1 to 3, which is characterized. 5. The first and second systems respectively include a main flow passage connecting a master cylinder and a wheel cylinder via a supply valve, and a master cylinder branched from the main flow passage via a discharge valve and pressure supply means. The first and second systems are connected by a communication part between the pressure supply means and the master cylinder, and a return path connected to the side is provided. Hydraulic circuit.