JPH038984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pneumatic booster used to assist pedal force when operating a brake master cylinder or a clutch master cylinder in automobiles, etc. , relates to an improvement in a device equipped with a mechanism that reduces play in the initial stage of operation.

(Prior Art) The present applicant first proposed a movable body movably inserted into an internal space formed inside a main body, which is equipped with a mechanism that reduces or eliminates the play at the initial stage of operation, and the movable body. a low-pressure chamber and a high-pressure chamber respectively partitioned on both sides of the movable body; a cylindrical portion provided on the other side of the movable body and movably penetrating the main body and projecting to the outside; an input member and an output member fitted movably from both sides of the inner hole; a plunger integrally provided with the input member and movable within the inner hole; A poppet valve body having a movable portion facing the provided valve seat and a valve seat provided on the inner wall of the inner hole so as to be seated thereon, respectively, and the plunger are placed in a non-operating position where the poppet valve body is separated from one of the valve seats. A valve device includes a biasing valve spring and controls communication between the low pressure chamber and the high pressure chamber and an external pressure source by relative displacement of the plunger with respect to the movable body; and a biasing device that biases the poppet valve body to seat on both valve seats in the valve device, and the biasing device is movably fitted into a hole provided in the movable body and has one end. has a shaft-like member that can come into contact with the main body on the high-pressure chamber side and whose other end projects toward the low-pressure chamber side, and an engaging portion that can be movably fitted into the inner hole and engaged with the plunger. An actuating member having a cylindrical portion and an arm portion extending from the cylindrical portion to be connected to the shaft member has been proposed.

To briefly explain the operation of this proposal, when the device is not in operation, when the movable body retreats until it comes into contact with the main body due to the large urging force of the return spring, the shaft-like member of the urging device is also pushed against the main body. As a result, the shaft-like member and the arm portion of the actuating member are positioned so as to move forward relative to the movable body, and naturally the cylindrical portion of the actuating member also moves forward relative to the movable body. The engaging portion of the shaped portion engages with the plunger to move the plunger forward relative to the movable body against the biasing force of the valve spring. Therefore, the poppet valve body moves forward equal to the amount of advance of the plunger, so it remains seated on the valve seat of the plunger.
Either reduce the distance between the valve seat and the valve seat provided on the inner wall of the inner hole, or move forward until it is seated on both valve seats.

When not in operation, the poppet valve body is seated on both valve seats, or is seated on the other valve seat while decreasing the distance from one valve seat, and input is transmitted to the input member. When the plunger moves, the poppet valve body either immediately leaves the other valve seat, or moves a little and then leaves the other valve seat, depending on the movement, and the poppet valve body disengages from the other valve seat after a slight movement. This allows the play in the initial stage of operation to be reduced or eliminated.

(Problem to be Solved by the Invention) However, in the above system, the plunger is moved forward against the biasing force of the valve spring in order to reduce or eliminate the play in operation, but the operation of moving the plunger forward The engaging portion of the member has a relatively small shape because it is engaged with the plunger within the inner hole, and if a large force such as pulling out the plunger is applied to the input member, the engaging portion will be deformed.
It becomes impossible to reduce the play or make it zero,
In some cases, there is a problem that the entire device malfunctions.

In other words, since a mechanism that reduces or eliminates play is built into the device, if an action force that pulls out the input member is applied before or during installation on an actual vehicle, such The function of the mechanism cannot be achieved due to the deformation of the engaging portion.

(Means for Solving the Problems) In the present invention, the actuating member is provided with a deforming portion that is elastically deformed when an acting force greater than the biasing force of the valve spring is applied.

(Function) When a large external force in the direction of withdrawal acts on the input member, this acting force is transmitted to the engaging portion of the actuating member by the plunger connected to the input member, and is combined with the biasing force of the valve spring to push the engaging portion. However, the deforming part is designed to elastically deform when a force greater than the biasing force of the valve spring is applied, so even if a large acting force is applied, the elastic deformation of the deformable part prevents the deformation from occurring. This prevents the engaging part from being permanently deformed, and after that, when the large acting force is no longer applied,
By restoring the deformation of the deformed portion, the device can be operated as intended.

(Example) FIG. 1 is a side sectional view showing the overall configuration of a negative pressure booster that is an example of the present invention, and FIG. FIG. 3 is a view in the direction of arrows showing only the actuating member, and FIG. 3 shows details of the auxiliary member for transmitting force shown in FIG. 1; FIG. be.
Note that in the drawings, those that are substantially the same as those of the conventional system will be briefly explained. Further, the front-rear direction is the left-right direction in FIG.

The negative pressure booster 1 has a main body 6 which is formed by combining a front shell 4 and a rear shell 5 with an outer peripheral bead 3 of a diaphragm 2 in between. This main body 6 forms a housing of the booster 1. This main body 6
A movable body 10 formed by joining a plate member 8 and a hub member 9 via the inner peripheral bead portion 7 of the diaphragm 2 is movably arranged inside. This movable body 10 together with the diaphragm 2 forms a low pressure chamber 11 on the front side and a high pressure chamber 12 on the rear side inside the main body 6. Main body 6 is rear shell 5
is supported by being fixedly attached to the vehicle body (not shown) with bolts and nuts (not shown), and a master cylinder (not shown) is similarly fixed to the front side of this main body with bolts and nuts (not shown). Closely mounted. The hub member 9 is generally cylindrical, with a rear portion 91 and a front portion 9.
2, and its small diameter rear portion 91
penetrates the central hole 34 of the rear shell 5 and projects to the outside.

A stepped inner hole 13 passing through the center of the hub member 9 has an output shaft 1 inserted through a retainer 14 on the front end side thereof.
5 is fitted, and the front end of the output shaft 15 is brought into contact with the bottom of the recess at the rear of the piston of the master cylinder. The retainer 14 is press-fitted into the end of the hub member 9 and held by its inward elastic claws 141. Behind the output shaft 15, a rubber disk 16 as a force transmitting member, a plunger 17, and an input shaft 18 coupled to the plunger 17 in a swingable manner and secured in the axial direction are arranged. A poppet valve body 23 is disposed so as to be seatable and opposite to a valve seat 21 provided on the outer periphery of the rear end of the plunger 17 and a valve seat 22 formed in a stepped portion of the stepped inner hole 13 on the radially outer side thereof. It is set up. This poppet valve body 2
3 has its rear end engaged with the step on the rear side of the stepped inner hole 13, and the front side portion 230 is movable. Between the poppet valve body 23 and the input shaft 18, there is a conical spring-shaped first portion 241 that biases the input shaft 18 rearward and a front portion 230 of the poppet valve body 23 that biases the front side portion 230 of the poppet valve body 23 forward. A valve spring 24 that is integrally formed with the second portion 242 is stretched.
The outer periphery of the front side portion 230 of the poppet valve body 23 is
It is constantly communicated with the negative pressure chamber 11 through a passage 25 provided in the hub member 9, and is further connected to a negative pressure source such as an engine intake manifold through a pipe (not shown). On the other hand, the inner peripheral side of the poppet valve body 23 is provided with a filter 2 disposed at the opening of the stepped inner hole 13.
It is in constant communication with the atmosphere through 6. Further, the outer periphery of the plunger 17 on the front side of the poppet valve body 23 is constantly connected to the high pressure chamber 1 through the passage 27 of the hub member 9.
I am contacting 2.

The poppet valve body 23, plunger 17, etc. constitute a valve device B. This valve device B
There are three types of control: One is a state in which the poppet valve body 23 is seated on the valve seat 21 and separated from the valve seat 22, in other words, the low pressure chamber 11 and the high pressure chamber 12 are communicated, and the high pressure chamber 12 and the atmosphere are in communication with each other. This is a state in which communication is cut off, and is a differential pressure eliminating position where the differential pressure between the high pressure chamber 12 and the low pressure chamber 11 is eliminated. The other is a state in which the poppet valve body 23 is seated on the valve seats 21 and 22, in other words, communication between the high pressure chamber 12 and the low pressure chamber 11, and communication between the high pressure chamber 12 and the atmosphere are both cut off. This is a differential pressure holding position where the differential pressure between the high pressure chamber 12 and the low pressure chamber 11 is kept constant. Furthermore, the poppet valve body 23 is separated from the valve seat 21 and the valve seat 22
In other words, the low pressure chamber 11 and the high pressure chamber 12 are disconnected from each other, and the high pressure chamber 12 is in communication with the atmosphere, and at the position where a differential pressure is generated. be. In particular, at the differential pressure generation position and differential pressure cancellation position, the range of these positions is
They are set at both ends of the movement range of the plunger 17 with respect to the movable body 10. In addition, the input shaft 18
The rear end is swingably pin-coupled to a pedal (not shown).

A hub member 9 housing such a valve device B inside
As described above, the rear portion 91, which is a cylindrical portion, passes through the hole 34 of the rear shell 5 and projects to the outside. The rear part of the rear shell 5 is narrower than the front part, and a hole 34 is formed inside the narrowed part 51. The movable body 10 is disposed between the inner peripheral surface of the hole 34 and the rear part 91. It is airtight so that it can be moved. That is, the boot 41 is arranged so as to cover almost the entire rear portion 91, and the rear end portion 42 is hooked and supported by the flange 36 of the metal fitting 35 fitted to the rear portion 91, while the front end portion 43 is a U-shaped sealing member that is sandwiched and supported between the constriction portion 51 and the rear portion 91. Also,
In order to prevent the front end portion 43 of the boot 41 from slipping out and to prevent the rear end portion 51 of the rear shell 5 from being bent inward, the front end portion 43 of the boot 41
3 is provided with a support ring 44 made of plastic and a stop ring 45 made of elastic material.

By the way, such a booster 1 includes a movable body 1
A return spring 32 that biases the front shell 4
and the movable body 10. Therefore, when the movable body 10 is not activated, the strong return spring 3
2, and the rib 33 of the diaphragm 2 is in contact with the inner surface of the rear shell 5.
At this time, the plunger 17 and the input shaft 18
Since the poppet valve body 23 is urged rearward by the valve spring 24, the poppet valve body 23 is conventionally seated on the inner valve seat 21, but unlike the illustrated state, the poppet valve body 23 is seated on the outer valve seat 22. He was sitting quite far away from the. The distance between the poppet valve body 23 and the valve seat 22 is the main cause of play in the booster 1 during its initial operation.

Therefore, in order to eliminate or reduce the initial operation play in the booster 1, the poppet valve body 23 is
It is effective to move the valve so that it is seated on both the inner and outer valve seats 21 and 22. To do this, move the input shaft 18 or the plunger 17 to the movable body 10 so that the amount of separation decreases or becomes zero.
All you have to do is move forward relative to that.

For this purpose, as proposed earlier, the following configuration is used.

That is, the booster 1 includes a pair of holes 60 provided in the outer peripheral side of the front portion 92 of the hub member 9 in the axial direction (one of them is omitted in FIG. 1 for convenience of drawing). The sealing member 61 can be moved freely to
a pair of movable pin members 62 fitted through the
An actuating member 70 assembled to the end of the pin member 62 on the low pressure chamber 11 side is used. A rubber cap 63 is attached to the end of the pin member 62 on the high pressure chamber 12 side, so that it comes into contact with the rear shell 5. Further, referring to FIG. 2, the connection between the pin member 62 and the actuating member 70 is achieved by inserting a pair of holes 72 provided at both ends of a pair of arms 71 of the actuating member 70 into the pin member 62 under low pressure. Room 11
The pin member 62 and the actuating member 70 are press-fitted and connected to a reduced diameter portion 64 provided at the side end.
It is now possible to move as one.
The central part of the actuating member 70 is a cylindrical part 74 that is movably fitted into the front end of the inner hole 13, and inside thereof, the output shaft 15 is arranged in order from the front side to the rear side. A diameter portion 151, a rubber disk 16 which is a force transmission member, and an auxiliary member 81 for force transmission whose detailed shape is shown in FIG. It is supported by the flange portion 75 of.

Referring to FIG. 3, the auxiliary member 81 mainly has an annular portion 82 on the front side, and a pair of arc-shaped protrusions 83 are formed protruding from the annular portion 82 on the rear side.

Returning to FIG. 1, the protruding portion 83 of the auxiliary member 81 is located at the small hole portion 1 of the inner hole 13 having the smallest diameter.
31, and the front end of the plunger 17 is fitted into its inner hole so as to be able to come into contact with the rubber disk 16. Further, a pair of inward protrusions 73 formed at the rear end of the actuating member 70 extend inwardly from between the pair of protrusions 83, and the protrusions 73 have an interval of 180 degrees,
It is positioned so as to be able to engage from the rear side with a C-ring-shaped stopper 85 attached near the front end of the plunger 17, and has a function as an engaging portion for the plunger 17. Therefore, the plunger 17 is
By engaging the stopper 85 with the protrusion 73 of the actuating member 70, the relative backward limit position with respect to the movable body 10 is defined. Further, the plunger 17 has its intermediate large diameter portion 171 brought into contact with the rear shoulder portion of the small hole portion 131, thereby defining the relative forward movement limit position with respect to the movable body 10.

Such a pin member 62 and operating member 70
is dimensioned to allow the plunger 17 to be advanced relative to the movable body 10 such that in the illustrated inoperative position, the distance between the valve seat 22 and the poppet valve body 23 is zero.

Now, here, the pair of arm portions 71 of the actuating member 70
has an end portion formed with a pair of holes 72 and a cylindrical portion 74.
It not only simply integrates the two, but also serves as a deformable part that deforms elastically when a predetermined force is applied. That is, the entire operating member 70 is
The first portion 241 of the valve spring 24 is made to have such rigidity that it will not be substantially elastically deformed only by the biasing force (the maximum value including the increase proportional to the spring constant due to the change in compression length). In addition, the width of the arm portion 71 in particular is made smaller compared to its length,
The protrusion 73 is set to be elastically deformed with an acting force that is slightly larger than the biasing force of the first portion 241 and that does not cause the protrusion 73 to deform. For example, the biasing force of the first portion 241 is 10 kg.
f. If the deformation starting force of the protrusion 73 is 20 kgf, the arm portion 73 may have a value between these values, for example, 12 to 18 kgf. These numerical values are shown as converted values as an acting force acting on the input shaft 18. Further, when the arm portion 73 actually deforms, the amount of deformation is only required until the stopper 85 of the plunger 17 comes into contact with the left shoulder portion of the small hole portion 131 via the protrusion 73, and the arm portion 73 is elastically deformed. The limit doesn't have to be that big.

In such a negative pressure booster 1, the stopper function of the pin member 62 and the actuating member 70 allows the retraction limit of the plunger 17 to be slightly advanced, thereby causing the poppet valve to close when not in operation. The body 23 comes to sit on both the inner and outer valve seats 21 and 22. This means that the operating play in the booster 1 itself is eliminated.

Therefore, when the input shaft 18 is moved forward by depressing a pedal (not shown), the valve device B is immediately switched to the differential pressure generating position. Then, the movable body 10 moves forward against the force of the return spring 32 due to the differential pressure, and the output shaft 1
5 is the moving force of the movable body 10 via the rubber disk 16 and the auxiliary member 81, and the rubber disk 1
6 and the plunger 17, and a pressing force, which is the sum of both moving forces, advances a piston of a master cylinder (not shown) to generate pressure. And input shaft 18
When the moving force (input) and the reaction force acting on the plunger 17 from the rubber disk 16 are balanced, the valve device B switches to the differential pressure holding position and the pressure generated in the master cylinder becomes constant.

During this time, the pin member 62 and the actuating member 70 are in a relatively free state, but are subjected to a forward biasing force due to an external force acting on them, that is, a differential pressure acting on the pin member 62, and furthermore, Due to the compression of the rubber disk 16 that occurs during operation, the frictional bonding force between the actuating member 70 and the rubber disk 16 increases, and as a result, the actuating member 70 tends to move together with the rubber disk 16. No trouble occurs in the operation of the booster 1.

On the other hand, when the pedal is no longer depressed, the input shaft 18 is returned to the rear by the force of the valve spring 24. This rearward moving force causes the plunger 17 to retreat, causing the stopper 85 and the protrusion 73 of the actuating member 70 to move backward.
The actuating member 70 and the pin member 62 engage with each other and move the actuating member 70 and the pin member 62 backward. At this time,
The pin member 62 and the actuating member 70 are connected to the plunger 17
As the protrusion 73 retreats, the protrusion 73 retreats until it comes into contact with the front shoulder of the small hole 131 , and the plunger 17 reaches its maximum retreat until it comes into contact with the front shoulder of the small hole 131 via the stopper 85 and the protrusion 73 . position and switch the valve device B to the differential pressure eliminating position. In this switching state, the low pressure chamber 11 and the high pressure chamber 12 communicate with each other and the differential pressure is eliminated, so that the movable body 10 returns to the spring 3.
It moves backward by the acting force of 2 and continues until just before it comes into contact with the rear shell 5. Therefore, the hyperbaric chamber 12
The atmospheric air sufficiently moves to the low pressure chamber 11 side, and is further suctioned sufficiently by a negative pressure source which is an external pressure source. As a result, both chambers 11 and 12 have approximately the same pressure and sufficient vacuum pressure.

The cap 63 at the rear end of the pin member 62 immediately before the movable body 10 comes into contact with the rear shell 5 comes into contact with the rear shell 5, and stops moving back integrally with the movable body 10.
Thereafter, the movable body 10 retreats until it comes into contact with the rear shell 5. Due to this retraction, the plunger 17 itself engages with the operating member 70 and stops retracting, and the distance between the poppet valve body 23 and the valve seat 22 decreases, and finally The poppet valve body 23 is seated on both valve seats 21 and 22 as shown in the figure.

Although this invention has been specifically described above based on Examples, it goes without saying that this invention is not limited to the above-mentioned Examples, and can be modified in various ways without departing from the gist thereof. Examples of changes are as follows.

(1) Although a pair of pin members 62, that is, two pin members are used, only one pin member 62 may be used. In this case, there is only one arm, so you can use this arm as the deformed part, or
Alternatively, the engaging portion may be a deformable portion.

(2) The engagement between the plunger 17 and the operating member 70 is as follows:
Although this is done using two protrusions 73, it may be three (120° apart), four (90° apart), or more. However, when the number of protrusions is small, it is preferable to provide them at equal intervals, and it goes without saying that at least the protrusions must have sufficient strength.

(3) Since the small holes 131 of the hub member 9 are repeatedly brought into contact with the front and rear shoulders of each member, a metal protection ring or the like may be arranged for strength reinforcement.

(4) Although it is most convenient to use the arm portion of the actuating member as the deforming portion, it is of course possible to use other parts as the deforming portion.

(5) The basic configuration of the booster is such that the input-output relationship is a pressing force, but the tow type that the applicant has already proposed (for example, the
58-85749).

(Effects of the Invention) In this invention, the actuating member, which is an important component of the mechanism for moving the plunger relatively forward, is provided with a deformable portion that elastically deforms when a force greater than the biasing force of the valve spring is applied. Not only when handling the device alone, but also when a large force is applied to the plunger etc. via the input member and this attempts to permanently deform the engaging part, the deformed part will elastically deform at any time and will not engage. It is possible to prevent permanent deformation of the main body, and furthermore, not only when acting from the input member, but also during operation after installation on an actual vehicle, the shaft-shaped member impacts the main body, causing impact to the operating member. If an excessive force is applied to the structure, the impact can be reduced by elastic deformation of the deformed portion, and the overall durability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the overall configuration of a booster according to an embodiment of the present invention, FIG. FIG. 3 is a diagram showing details of the auxiliary member shown in FIG. 1, with FIG. 3A showing a side sectional view and FIG. 3B showing a front view. 1... Negative pressure booster, 6... Main body, 91...
Rear part (cylindrical part), 10...Movable body, 11...Low pressure chamber, 12...High pressure chamber, 13...Inner hole, 15...
...Output shaft (output member), 17...Plunger, 1
8... Input shaft (input member), 21... Valve seat (plunger side), 22... Valve seat (inner hole side), 23... Poppet valve body, 24... Valve spring, 32... Return spring, B... Valve device, 70... Operating member, 71...
Arm portion, 74...cylindrical portion.

Claims (1)

[Claims] 1. A movable body movably inserted into an internal space formed inside the main body, a low-pressure chamber and a high-pressure chamber partitioned on both sides of the movable body, and a movable body provided on the other side of the movable body so that the main body can be moved. a cylindrical portion that penetrates through the tube and projects to the outside; an inner hole that penetrates the cylindrical portion and the movable body; and an input member and an output member that are movably fitted into each other from both sides of the inner hole; A poppet having a plunger integrally provided with the input member and movable within the inner hole, and a movable portion facing the valve seat provided on the plunger and the valve seat provided on the inner wall of the inner hole so as to be able to sit on each of them. The movement of the plunger includes a valve spring that urges the valve body and the plunger to a non-operating position in which the poppet valve body is separated from one valve seat, and controls communication between the low pressure chamber and the high pressure chamber and an external pressure source. A valve device that operates by relative displacement with respect to the valve body, and an urging device that moves the plunger against a valve spring when not in operation and urges the poppet valve body to seat on both valve seats in the valve device. The biasing device includes a shaft-like member movably fitted into a hole provided in the movable body, one end of which is capable of abutting against the main body on the high-pressure chamber side, and the other end of which protrudes toward the low-pressure chamber side; an actuating member having a cylindrical part having an engaging part movably fitted into the inner hole and capable of engaging with the plunger; and an arm part extending from the cylindrical part to be connected to the shaft member; A pneumatic booster comprising: a deformable portion that elastically deforms when a force greater than the biasing force of the valve spring is applied to the actuating member.