JPH0911887A - Negative pressure type booster - Google Patents

Abstract

PURPOSE: To downsize and simplify a sensor to detect whether a negative pressure type booster is put in a restoration stopping condition or in any actuating condition. CONSTITUTION: A contact condition of an air valve 51 and a sealing part 53a of a control valve 53 is electrically detected by using conductive rubber in the sealing part 53a of the control valve 53. Conductive rubber 46 to allow shaft directional movement of a stopper 45 to a cylinder member 23 is arranged between the stopper 45 and the cylinder member 23, and a contact condition of this conductive rubber 46 and the stopper 45 is electrically detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative pressure type booster used as one component of a vehicle brake device, for example.

[0002]

2. Description of the Related Art As one of negative pressure type boosters, a movable wall that divides the inside of a housing into a constant negative pressure chamber and a variable pressure chamber, and a movable wall integrally provided at the center of the movable wall to the outside of the housing. A cylindrical member that extends, a plunger that is concentrically fitted in the cylindrical member and is slidable in the axial direction, and is integrally connected to the plunger and is connected to the outside of the cylindrical member through an outer end opening of the cylindrical member. An extending input rod, a first urging means for urging the input rod to the outside of the cylindrical member, and an urging means for the first urging means which is attached to the cylindrical member so as to be movable in a predetermined axial direction. A stopper that defines the amount of movement of the plunger with respect to the cylindrical member due to the force, an annular vacuum valve that is formed on the inner surface of the cylindrical member so as to project toward the outer end opening, and is provided coaxially within the vacuum valve. The above plan And an annular air valve capable of interlocking with the air valve and an annular seal portion facing the air valve and the vacuum valve at one end, and the other end being airtightly fixed to the inner surface of the cylindrical member. A valve, a second urging means for urging the seal portion of the control valve toward the air valve and the vacuum valve, and the air valve and the second valve which are assembled to the cylindrical member to drive the movable core by excitation. An electromagnetic solenoid for disengaging a control valve is provided, and the valve is switched by the control valve by the pushing operation of the plunger by the input rod or the driving operation by the excitation of the electromagnetic solenoid, and the constant negative pressure chamber and the There is a system in which a pressure difference is generated between the variable pressure chambers and a propulsive force is generated in the movable wall. Patent Application Publication Specification No. 4211849 (DE 4211849 A
1), European Patent Publication No. 620789 (EP 6)
20789 A1) and the like. In the negative pressure type booster shown in German Patent Application Publication No. 4211849, the air valve is driven to the output side by the excitation of the electromagnetic solenoid, and the engagement between the air valve and the control valve is released ( Atmosphere is introduced to the transformer room), and European Patent Publication No. 6
In the negative pressure type booster shown in 20789, the control valve is driven to the input side by the excitation of the electromagnetic solenoid, and the engagement between the air valve and the control valve is released.

[0003]

In the negative pressure type booster of the type described above, when the operation of the device is controlled electrically by exciting an electromagnetic solenoid, particularly in an analog manner, the moving state of the movable core, etc. Is required to detect whether the device is in a return stop state or in what operating state, and a small and simple configuration is required for this sensor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demands, and in a negative pressure type booster of the type described above, a conductive rubber is used for the seal portion of the control valve. The state of contact between the air valve and the seal portion of the control valve can be electrically detected. In addition to the above configuration, a conductive rubber that allows axial movement of the stopper with respect to the cylindrical member is disposed between the stopper and the cylindrical member to prevent contact between the conductive rubber and the stopper. It is configured to be electrically detectable.

[0005]

The negative pressure booster according to the present invention (constituted by electrically conductive rubber for the seal portion of the control valve to electrically detect the contact state between the air valve and the seal portion of the control valve) ), The air valve changes from the closed state (state in contact with the seal part) to the open state (state in which it is separated from the seal part) due to changes in the contact state between the air valve and the control valve seal part. The process of opening and the process of transitioning from the open state to the closed state can be detected. Therefore, the sensor constituted by the air valve and the control valve sealing portion can be effectively utilized as a sensor for electrically, particularly analogically controlling the operation of the apparatus by exciting the electromagnetic solenoid.

Further, in the above-mentioned device of the present invention,
The control valve seal uses conductive rubber to construct a sensor that detects the opening / closing process of the air valve using the air valve and the control valve seal, and effectively utilizes the existing components of the device. Since the sensor is configured, the sensor can be made small and simple, and the device can be implemented inexpensively without increasing the size.

Further, the negative pressure type booster according to the present invention is constructed such that a contact state between the air valve and the control valve seal portion can be electrically detected by using a conductive rubber for the control valve seal portion. A conductive rubber that allows the stopper to move in the axial direction with respect to the cylindrical member is disposed between the stopper and the cylindrical member so that a contact state between the conductive rubber and the stopper can be electrically detected. In, in accordance with the change in the contact state between the air valve and the control valve seal portion, it is possible to detect the process of the air valve transitioning from the closed state to the open state and the process of transitioning from the open state to the closed state, respectively. The movement of the plunger relative to the cylindrical member may change due to changes in the contact status between the stopper and the conductive rubber that is placed between the stopper and the cylindrical member. And can be detected, it can be the device detects it is in any operating condition it is in the return stop state. Therefore, the sensor composed of the seal part of the air valve and the control valve and the sensor composed of the conductive rubber and the stopper arranged between the stopper and the cylindrical member are electrically, particularly It can be effectively used as a sensor for analog control.

Further, in the above-mentioned device of the present invention,
A conductive rubber is used for the control valve seal to form a sensor that detects the opening / closing process of the air valve by the air valve and the control valve seal, and the stopper moves axially with respect to the cylindrical member between the stopper and the cylindrical member. A sensor for detecting the moving state of the plunger with respect to the cylindrical member is configured by disposing an allowable conductive rubber and the conductive rubber and the stopper, and each sensor by effectively utilizing the existing constituent members of the device. Since each of the sensors is configured as described above, each sensor can have a small size and a simple structure, and the device can be implemented inexpensively without increasing the size thereof.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example in which the present invention is applied to a tandem type negative pressure type booster used in a vehicle brake device. A housing 10 of this negative pressure type booster has a master cylinder (not shown) in the front. It is composed of a cup-shaped front shell 11 to be mounted, and a plate-shaped rear shell 12 that is airtightly assembled to the rear end of the front shell 11 and mounted to the dashboard (not shown) of the vehicle body at the rear, Partition 1 inside
A cylindrical member 2 that hermetically penetrates substantially the center of the partition wall 13
Front and rear movable walls 2 connected to each other by 3
Two constant negative pressure chambers R1 and R2 and a variable pressure chamber R
It is divided into four chambers R3 and R4. The constant negative pressure chambers R1 and R2 are provided in the cylindrical member 23 through the through hole 23b in the axial direction.
And always communicate with each other through a radial through hole 23c. Further, the variable pressure chambers R3, R4 are always communicated with each other through an axial through hole 23d provided in the cylindrical member 23 and a radial through hole 23e.

The front shell 11 has a master cylinder mounting plane portion reinforced by a lean force 14 provided inside thereof, and a bolt 15 for mounting the master cylinder also penetrates the lean force 14 on the master cylinder mounting plane portion. Then, a connector 16 connected to an intake manifold (a negative pressure source (not shown)) of the engine is airtightly attached to the outer peripheral portion of the flat surface of the master cylinder. On the other hand, the rear shell 12 has a body mounting flat portion in the rear center portion, and a bolt 17 for mounting the booster to the dashboard is airtightly mounted on the body mounting flat portion.

The front movable wall 21 is an annular plate 21.
a and an annular diaphragm 21b. The plate 21a is fitted to the rear surface of the front end outward flange of the cylindrical member 23 at the inner peripheral portion. Diaphragm 21
b is provided on the rear surface of the plate 21a, the inner peripheral bead portion is airtightly fitted to the front step portion of the cylindrical member 23,
The outer peripheral bead portion is airtightly fitted between the intermediate step portion of the front shell 11 and the intermediate step portion of the partition wall 13. on the other hand,
The rear movable wall 22 is composed of an annular plate 22a and an annular diaphragm 22b. The plate 22a is fitted to the intermediate step portion of the cylindrical member 23 at the inner peripheral portion. The diaphragm 22b is provided on the rear surface of the plate 22a, the inner peripheral bead portion is airtightly fitted to the intermediate step portion of the cylindrical member 23, and the outer peripheral bead portion is located at the outer peripheral step portion of the rear shell 12 and the partition wall 13. It is hermetically fitted between the ends.

The cylindrical member 23 is made of an insulating resin, has a small-diameter cylindrical portion 23a protruding outside the housing 10 through the seal member 31 and the bush 32, and is a compression coil interposed between the lean forces 14. The spring 70 is engaged via the retainer 24 and the electromagnetic solenoid S to be urged rearward, the valve mechanism V is incorporated inside the rear portion, and the reaction force mechanism A is attached in the front portion. . Further, the small-diameter cylindrical portion 23a of the cylindrical member 23 is
The outer periphery thereof is covered and protected by a boot 33, and the inside of the rear is communicated with the atmosphere through an air filter F attached to an opening end and a through hole 33a provided in the boot 33.

The valve mechanism V is for connecting both the variable pressure chambers R3 and R4 to the constant pressure chambers R1 and R2 or the atmosphere.
As shown in detail in an enlarged manner in FIG. 2, an annular air valve 51 mounted on the outer periphery of the plunger 41 via a seal ring 49 so as to be airtight and axially movable, and the inner surface of the inner hole of the cylindrical member 23. An annular vacuum valve 52 integrally formed to project toward the rear opening (outer end opening), and a tubular shape assembled in the small-diameter tubular portion 23a of the cylindrical member 23 corresponding to these both valves 51, 52. The control valve 53 and the like. The plunger 41 is made of a conductive material, and is concentrically and axially slid in the cylindrical member 23 in a state of being connected to the tip of an input rod 42 interlocking with a brake pedal (not shown) via a ball joint 43. It is movably fitted, and the axial movement amount with respect to the cylindrical member 23 is regulated to a predetermined amount by a stopper 45. The input rod 42 is made of a conductive material, has a ball joint 43 integrally at its tip, and is engaged via a retainer 44 by a compression coil spring 71 interposed between holders 54 holding a control valve 53. They are aligned with each other and are urged toward the rear opening of the cylindrical member 23, and are grounded to the body of the vehicle.

The stopper 45 is a rectangular plate made of a conductive material and regulates the amount of movement of the plunger 41 with respect to the cylindrical member 23 by the urging force of the compression coil spring 71, as shown in FIGS. Is attached to a mounting hole (hole having a rectangular cross section) 23f provided in the cylindrical member 23 together with the conductive rubber 46 so as to be movable in a predetermined amount in the axial direction.
It is engaged with the plunger 41 at the tip. Further, since a cushioning rubber 47 is attached to a portion of the stopper 45 that contacts the rear shell 12, the stopper 45 is body-grounded via the plunger 41 and the input rod 42. The conductive rubber 46 is assembled to the cylindrical member 23 together with the holder 48 made of a conductive material in a curved shape, and is elastically engaged with the stopper 45 at the tip. The holder 48 is formed in a shape that abuts on the stopper 45 in a state where the conductive rubber 46 is bent by a predetermined amount, and a lead wire L1 that hermetically penetrates the front shell 11 is connected to the holder 48. It is possible to energize 46.

The control valve 53 has an annular seal portion 53a facing the air valve 51 and the vacuum valve 52 at the front end, and the rear end mounting portion 53c insulates the inner surface of the small diameter cylindrical portion 23a of the cylindrical member 23. It is airtightly fixed by a holder 54 made of a material, and has a cylindrical expansion / contraction part (bellows part) 53b which is expandable / contractible in the axial direction in the middle part. The control valve 53 is made of conductive rubber, and a lead wire L2 that hermetically penetrates the front shell 11 is connected to the rear end mounting portion 53c so that it can be energized. Control valve 5
3, the above-mentioned seal portion 53a is backed up and held by an annular plate 55 formed of an insulating material, and a compression coil spring 72 interposed between the holder 54 and the plate 55 allows the seal portion 53a to be connected to both valves 5.
It is urged toward 1, 52 so that the seal portion 53a selectively engages with each valve 51, 52. When the control valve 53 is engaged with the air valve 51 and is separated from the vacuum valve 52 as shown in the figure, the variable pressure chamber R4 is formed through the radial through hole 23g formed in the outer periphery of the air valve 51 and provided in the cylindrical member 23. An annular chamber that is always in communication with the through hole 23b formed in the outer periphery of the vacuum valve 52 and provided in the cylindrical member 23 is always in communication with the through hole 23b (which is in communication with the constant negative pressure chambers R1 and R2). It communicates with the circular chamber.

The air valve 51 is made of a conductive material, and is biased toward the control valve 53 by a compression coil spring 73 made of a conductive material interposed between the plungers 41.
Is integrally connected to the compression coil spring 73.
The body is grounded via the plunger 41 and the input rod 42. The movable core 81 is formed of a magnetic material in a cylindrical shape, and is concentrically assembled in the cylindrical member 23 together with the electromagnetic solenoid S and the electromagnetic solenoid S.
The sleeve 82 (formed of a non-magnetic material) is slidably assembled in the axial direction.

The electromagnetic solenoid S is assembled to the cylindrical member 23 via a seal ring 89 and is excited to move the movable core 81 and the air valve 51 to a compression coil spring 73.
And is constituted by an electromagnetic coil 84 and a fixed core 85 and the like assembled in the solenoid body 83 together with the sleeve 82.
A lead wire L3 that hermetically penetrates the front shell 11 is connected to the wire 4 so that it can be energized.

The reaction force mechanism A is provided on the fixed core 85 and the output rod 91 in which the rear end flange portion 91a is axially slidably fitted in the large diameter portion of the stepped inner hole formed in the fixed core 85. Disk-shaped reaction rubber disk 92 that is housed in the large diameter portion of the stepped inner hole and abuts the stepped portion of the stepped inner hole, and the medium diameter portion and the small diameter portion of the stepped inner hole provided in the fixed core 85. The reaction force (the pressure between the constant negative pressure chambers R1 and R2 and the variable pressure chambers R3 and R4) that is slidably fitted in the axial direction and is obtained by the deformation of the reaction rubber disk 82 when the negative pressure type booster is operated. The spool 93 is configured to transmit a force corresponding to the propulsive force generated in the movable walls 21 and 22 due to the difference) to the plunger 41. The front end of the output rod 91 is shown in FIG.
Through the seal member 18 as shown in FIG.
It projects outward and engages with a piston of a master cylinder (not shown).

In the negative pressure type booster of the present embodiment constructed as described above, the pushing operation of the plunger 41 by the input rod 42 in the usable state (the air valve 51 is integrally formed through the movable core 81). The air valve 51 is pushed and the spring 73 is not compressed) or the driving operation is performed by exciting the electromagnetic solenoid S (the air valve 51 is driven independently of the plunger 41 by the movement of the movable core 81 and the spring 73 is compressed). Is separated from the control valve 53, the control valve 5
3 is switched to block the communication between the constant negative pressure chambers R1 and R2 and the variable pressure chambers R3 and R4, and the atmosphere is introduced into the variable pressure chambers R3 and R4, so that the constant negative pressure chambers R1 and R2.
And a pressure difference between the variable pressure chambers R3 and R4,
Propulsive force is generated in 22 to move the cylindrical member 23 and each member attached thereto against the compression coil spring 70,
A predetermined boosting characteristic can be obtained.

Further, in the negative pressure type booster of the present embodiment, the change of the contact state between the air valve 51 and the seal portion 53a of the control valve 53, that is, the air valve 51 controls as shown in FIG. Valve 53
The air valve 51 is in the closed state (contact with the seal portion 53a) due to an increase change in the contact resistance value caused by moving to the left or right of FIG. 1 and FIG. It is possible to detect the process of transition from the open state (the state of being separated from the seal portion 53a) and the process of transition from the open state to the closed state, and the stopper 45 and the cylindrical member 23.
A change in the contact state between the conductive rubber 46 and the stopper 45 arranged between them, that is, as shown in FIG.
1 and FIG. 2 with respect to the cylindrical member 23, or by returning to the left after that, due to the decrease change of the contact resistance value and vice versa increase, the cylindrical member 2
The movement state of the plunger 41 with respect to 3 can be detected, and it can be detected whether the device is in the return stop state or in what operating state. Therefore, the seal portion 5 of the air valve 51 and the control valve 53 is
3a, the stopper 45, and the cylindrical member 23.
The sensor constituted by the conductive rubber 46 and the stopper 45 arranged between them can be effectively utilized as a sensor when the operation of the device is electrically controlled by exciting the electromagnetic solenoid S, particularly in an analog manner. The movement amount D1 shown in FIG. 4 corresponds to the amount of bending of the seal portion 53a by the air valve 51, and the contact resistance value at that time (when the air valve 51 separates from the seal portion 53a) is very large. It becomes a value. In addition, the movement amount D2 shown in FIG.
Corresponds to the maximum bending amount of the conductive rubber 46,
At that time, the stopper 45 contacts the holder 48 and the contact resistance value becomes substantially zero.

In the present embodiment, the air valve 51 and the seal portion 53 of the control valve 53 are made of conductive rubber for the seal portion 53a of the control valve 53.
a constitutes a sensor for detecting the opening / closing process of the air valve 51, and a conductive rubber 46 which allows the stopper 45 to move in the axial direction with respect to the cylindrical member 23 is provided between the stopper 45 and the cylindrical member 23. The rubber 46 and the stopper 45 constitute a sensor that detects the movement state of the plunger 41 with respect to the cylindrical member 23. Since each sensor is configured by effectively utilizing the existing constituent members of the device, The sensor can have a small size and a simple structure, and the device can be implemented inexpensively without increasing the size.

In the above embodiment, an example in which the contact resistance between the conductive rubber and the metal surface is detected has been shown. However, there are conductive rubbers whose conductivity changes in a switching manner depending on the contact pressure. In place of this embodiment, ON-OF
It is easy to detect the opening and closing of the F-like valve. Further, in the above embodiment, the present invention is applied to the tandem type negative pressure type booster, but the present invention is applicable not only to the single type negative pressure type booster but also to the triple type negative pressure type booster. It can be similarly implemented. Further, in the above embodiment, the negative pressure type booster in which the air valve is driven to the output side by the excitation of the electromagnetic solenoid so that the engagement between the air valve and the control valve is released (the atmosphere is introduced into the variable pressure chamber). The present invention has been implemented in the same manner, but the present invention is also implemented in a negative pressure type booster in which the control valve is driven to the input side by the excitation of the electromagnetic solenoid so that the engagement between the air valve and the control valve is released. It is possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a negative pressure type booster according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view showing the relationship among the cylindrical member, stopper, conductive rubber, and holder shown in FIG.

FIG. 4 is a diagram showing a relationship between a contact resistance value generated between a seal portion of an air valve and a control valve and a movement amount of the air valve with respect to the seal portion of the control valve.

FIG. 5 is a diagram showing a relationship between a contact resistance value generated between a stopper and a conductive rubber and a movement amount of the stopper with respect to a cylindrical member.

[Explanation of symbols]

10 ... Housing, R1, R2 ... Constant negative pressure chamber, R3, R4
... Transforming chamber 21,22 ... Movable wall, 23 ... Cylindrical member, 41
… Plunger, 42… Input rod, 45… Stopper, 4
6 ... Conductive rubber, 51 ... Air valve, 52 ... Vacuum valve, 53 ... Control valve, 53a ... Seal part, 53b ... Cylindrical expansion / contraction part, 71 ... Compression coil spring (first urging means), 72 ... Compression coil spring (Second
Urging means), 81 ... movable core, S ... electromagnetic solenoid.

Claims (2)

[Claims] 1. A movable wall that divides the inside of the housing into a constant negative pressure chamber and a variable pressure chamber, a cylindrical member that is integrally provided at the center of the movable wall and extends outside the housing, and the cylindrical member. A plunger fitted concentrically and slidably in the axial direction, an input rod integrally connected to the plunger and extending from the outer end opening of the cylindrical member to the outside of the cylindrical member, and the input rod For urging the outside of the cylindrical member
Urging means, a stopper movably assembled to the cylindrical member in the axial direction by a predetermined amount, and defining a movement amount of the plunger with respect to the cylindrical member by the urging force of the first urging means; An annular vacuum valve formed on the inner surface so as to project toward the outer end opening, an annular air valve coaxially provided in the vacuum valve and capable of interlocking with the plunger, the air valve and the vacuum valve. A control valve having opposed annular seal portions at one end and airtightly fixed to the inner surface of the cylindrical member at the other end, and the control valve seal portions are directed toward the air valve and the vacuum valve. Second urging means for urging the movable member and the air valve and the control unit which are assembled to the cylindrical member to drive the movable core by excitation. An electromagnetic solenoid for releasing the engagement of the valve, the control rod performs valve switching by the pushing operation of the plunger by the input rod or the driving operation by the excitation of the electromagnetic solenoid, and the constant negative pressure chamber and the transformer. In a negative pressure type booster in which a pressure difference is generated between the chambers and a propulsive force is generated in the movable wall, a conductive rubber is used for a seal part of the control valve, and the air valve and the seal part of the control valve are used. A negative pressure type booster characterized by being configured to electrically detect the contact state of the. 2. The negative pressure type booster according to claim 1, wherein a conductive rubber is provided between the stopper and the cylindrical member to allow axial movement of the stopper with respect to the cylindrical member. A negative pressure type booster characterized in that a contact state between rubber and the stopper can be electrically detected.