JPH0349086Y2 - - Google Patents

Description

[Detailed Description of the Invention] a. Field of Industrial Application The present invention relates to a spring holder for a master cylinder piston, and in particular to a return spring that biases the master cylinder piston toward the backward movement side, and a return spring disposed on the master cylinder piston. The present invention relates to a spring receiver that receives a compression spring that urges a valve in a closing direction.

b. Prior Art As this type of spring holder 1, for example, the one shown in FIG. 5 is conventionally known. This figure schematically shows the front end of a tandem type master cylinder. When the input rod 2 is pushed in the direction of arrow a in Fig. 5 by depressing the brake pedal, this force is transferred to another not shown It acts on the piston 3 via another piston and a spring, and the piston 3 moves forward in the direction of arrow b in FIG. It is designed to be fed under pressure into a cylinder.

By the way, the spring receiver 1 is attached to the front end of the piston 3. For details, see Piston 3
A spring receiver 1 is attached to cover the opening of a recess 7 formed in the front wall of the spring receiver 1, and one end of the return spring 4 is received by the flange 1a of the spring receiver 1. A cup seal ring 8 is fixed to the piston 3 by 1a. Further, one end of a compression spring 10 that biases the valve 9 disposed in the recess 7 in the closing direction is also received by the spring receiver 1. Spring bracket 1
One end constitutes a cylindrical boss portion 1b, and this boss portion 1b is fitted into the inner circumferential surface of the recess 7.
The spring receiving fitting 1 and the piston 3 are interconnected by a C-shaped ring 11 disposed on this fitting surface.

Note that the passage 12 formed along the axial direction of the piston 3 normally communicates the oil reservoir 13 and the discharge port with each other, but when the piston 3 moves forward and backward, the passage 12 is connected to the valve 9. It is now possible to close and open the door.

c Problems to be solved by the invention Conventional spring holder for master cylinder piston 1
Although the spring receiving fitting 1 is roughly constructed as described above, the following problems have been pointed out.
That is, since the conventional spring receiving fitting 1 was a molded product, a certain degree of wall thickness was required as a minimum, and accordingly more space was required in the axial direction of the master cylinder. Also spring holder 1
is assembled by the ring 11, it is necessary to cut the ring groove 14 on both the spring holder 1 and the inner circumferential surface of the recess 7 of the piston 3, which increases the cost and further increases the cost of the spring holder 1. The assembly work was also quite troublesome.

Also, although this is not a problem with the spring holder 1 itself, the deformation of the cup seal ring 8 becomes quite large due to the oil flowing in the direction of the arrow from the small hole of the piston when the brake pedal is depressed repeatedly, a so-called pumping brake operation. If this deformation becomes too large, there is a risk of damaging the ring. Therefore, there has been a demand for a means to suppress the deformation of the cap seal ring, but due to space constraints, no effective countermeasure has been implemented to date.

The present invention was devised to effectively solve the above-mentioned problems, and its purpose is to reduce the cost, reduce the size and weight of the spring holder, and improve the ease of assembly. It also has the function of suppressing deformation of the seal ring.

d Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a method in which a passage is formed along the axial direction of the master cylinder piston, and the front end of the passage is formed in the front wall of the master cylinder piston. a valve that communicates with the recess, a rear end of the passage communicating with an oil reservoir, and that closes and opens the passage in conjunction with the forward and backward movement of the master cylinder piston within the recess; A cup seal ring is fitted to the outer circumferential surface of the front end of the master cylinder piston, and a lip portion of the cup seal ring communicates with an oil reservoir on the rear side of the lip portion of the cup seal ring. In the master cylinder piston in which a small hole is formed and the master cylinder piston is urged in the backward direction by a return spring, an annular circular plate made of sheet metal is disposed in contact with the front wall of the master cylinder piston. The metal fitting has a first bent portion extending toward the front side of the cup seal ring and a second bent portion extending toward the front side of the master cylinder piston at a plurality of locations on the outer peripheral edge of the metal fitting. respectively forming the curved portions, and forming the first curved portion.
and the outer peripheral edge excluding the second bent portion is a first spring receiving portion, and the first spring receiving portion receives one end of the return spring, and one end of the return spring is connected to the second spring receiving portion. Positioning is controlled by the bent portion, and third bent portions extending into the recess and fitting into the inner wall of the recess are formed at a plurality of locations on the periphery of the hole formed in the center of the metal fitting; The peripheral edge of the hole of the metal fitting except for the bent portion No. 3 is used as a second spring receiving portion, and one end of the compression spring is received by the second spring receiving portion.

e Function In the spring receiving fitting for the master cylinder piston constructed as described above, each bent portion can be formed by cutting and cutting the peripheral edge of the annular disc, so that cost can be reduced and the fitting can be Since it is plate-shaped, the space in the axial direction of the piston is hardly increased compared to conventional molded products, and the third bent part of the spring receiver fits into the inner wall of the valve housing recess of the piston. This allows the metal fitting to be fixed to the piston, so there is no need for any special parts to attach the metal fitting.Furthermore, the metal fitting can be attached to the piston with one touch, improving the efficiency of assembly work. In addition, even if the cup seal ring of the piston tries to deform due to the flow of oil due to pumping brake operation, the first bent part of the spring holder suppresses the deformation, preventing damage to the cup seal ring. be prevented.

f Example An example of the present invention will be described below based on the drawings. FIG. 1 shows a master cylinder piston 19 equipped with a spring holder 18 according to the present invention and the structure around the master cylinder piston 19. As shown in the figure, the piston 19
A passage 20 is formed in the interior along the axial direction, and an oil reservoir 21 and an oil discharge port 22 are normally in communication with each other via this passage 20. Note that the oil discharge port 22 is connected to each wheel cylinder.

The passage 20 communicates with a recess 23 formed in the front wall of the piston 19. A valve 24 is disposed within this recess 23, and when the piston 19 moves back and forth, the passage 20 is closed and closed by this valve 24.
It is starting to open up. The valve 24 has a rod portion 25 extending forward and backward in the axial direction.
It has 26. Tip 25a of front rod portion 25
is inserted into a locking hole 28 of the spring retainer 27, and when the piston 19 moves back, the tip 25a is locked in the locking hole 28 and the valve 24 is opened. The rear rod portion 26 is slidably inserted into the passage 20 of the piston 19 to stabilize the valve 24.

The spring receiving fitting 18 is arranged on the front wall of the piston 19. This spring holder 18 is shown in Figures 2 to 4.
As shown in the figure, a circular sheet metal is press-formed, and a plurality of parts of the outer peripheral edge constitute a first bent part 31 bent rearward, and another plurality of parts of the outer peripheral edge constitute a first bent part 31 bent rearward. This portion constitutes a second bent portion 32 bent forward, and the remaining portion of the outer peripheral edge portion constitutes a first spring receiving portion 33. As shown in FIG. 1, the first bent portion 31 extends to the front side of a cup seal ring 34 disposed on the outer periphery of the front end of the piston 19, and when the pumping brake is operated, the seal ring 34 has a small hole. When trying to deform due to the flow of oil gushing from 35, the first
The deformation is suppressed by being pressed by the bending portion 31 of. The first spring receiving part 33 receives one end of the return spring 36, and the first spring receiving part 33 receives one end of the return spring 36.
The piston 19 is energized in the backward direction. Note that the second bent portion 32 regulates the positioning of one end of the return spring.

On the other hand, an insertion hole 39 is provided in the center of the spring holder 18.
is formed, and the rod portion 25 of the valve 24 is inserted into this insertion hole 39. A plurality of locations on the inner circumferential edge of the insertion hole 39 constitute a third bent portion 40 bent rearward as shown in FIGS. 2 to 4, and the remaining portions of the inner circumferential edge constitute a second It constitutes a spring receiving part 41. More specifically, as shown in FIGS. 3 and 4, the third bent portion 40 has its tip slightly expanded radially outward in its natural state. When the third bent portion 40 is pushed into the inner circumferential wall of the recess 23 of the piston 19 as shown in FIG. is fixed to the piston 19. Second
The spring receiving portion 41 receives one end of a compression spring 42, and the compression spring 42 biases the valve 24 in the closing direction. Note that the third bending portion 40
regulates the positioning of one end of the compression spring 42.

The spring holder 18 of the master cylinder piston is constructed as described above, and in addition to having the same function as the conventional spring holder, the spring holder 18 has the same function as the conventional spring holder.
It also has the function of suppressing deformation. In other words, during pumping brake operation, the piston 19
When moving back to the right in the figure, the oil in the cylinder flows to the left in Figure 1 through the small hole 35 of the piston 19, and this oil flow causes the cup seal ring 34 to close as shown in Figure 1. Attempts to deform to the left. However, since the first bent portion 31 of the spring holder 18 extends from the front side of the cup seal ring 34, deformation of the cup seal ring 34 beyond a certain level is prevented, and unexpected damage to the seal ring 34 is prevented. is prevented.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. The number, shape, etc. can be changed as necessary.

g. Effects of the invention As described above, the present invention constructs a spring holder using sheet metal, and the third bent part provided on the metal fitting is fitted into the valve housing recess of the piston to form the spring holder. Since it is attached to the piston, there is no need for any special parts for attaching the spring receiver, thus improving the efficiency of the spring receiver attachment work and reducing the number of parts. In addition, since the spring holder is made of sheet metal and is obtained by cutting and bending the bent portion, it is easy to process and can be manufactured at low cost.Furthermore, since it is thin, the axis of the master cylinder This can contribute to shortening the directional space. Furthermore, since the first bent portion of the spring holder extends toward the front side of the cup seal ring of the piston, the deformation of the seal ring when the piston moves back is prevented by the first bent portion. This can prevent accidental damage to the seal ring.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional view of the front end of the master cylinder, Figure 2 is a front view of the spring holder, and Figure 3 is a vertical sectional view of the front end of the master cylinder. FIG. 2 is a sectional view taken along the - line in FIG. 2, and FIG. 4 is a sectional view taken along the - line in FIG. FIG. 5 is a longitudinal sectional view of the front end of a conventional master cylinder. 18... Spring holder, 19... Master cylinder piston, 20... Passage, 21... Oil reservoir, 22... Oil discharge port, 23... Recess, 24
... Valve, 31... First bent part, 32... Second bent part, 33... First spring receiving part, 34...
Cup seal ring, 35...Small hole, 36...Return spring, 40...Third bent portion, 41...Second spring receiving portion, 42...Compression spring.

Claims (1)

[Scope of utility model registration request] A passage is formed along the axial direction of the master cylinder piston, the front end of the passage communicates with a recess formed in the front wall of the master cylinder piston, and the rear end of the passage communicates with the oil reservoir. A valve that closes and opens the passage in conjunction with the forward and backward movement of the master cylinder piston, and a compression spring that biases the valve in the closing direction are respectively disposed in the recess. A cup seal ring is fitted to the outer peripheral surface of the front end, and a small hole communicating with the oil reservoir is formed at the rear side of the lip of the cup seal ring, and the master cylinder piston is moved in the backward direction by a return spring. In the master cylinder piston that has been energized, an annular circular metal fitting made of sheet metal is disposed in contact with the front wall of the master cylinder piston, and the cup seal ring is attached at multiple locations on the outer peripheral edge of the metal fitting. a first bent portion extending toward the front side of the master cylinder piston, and a second bent portion extending toward the front of the master cylinder piston, respectively;
The outer peripheral edge portion excluding the first and second bent portions is a first spring receiving portion, and the first spring receiving portion receives one end of the return spring, and one end of the return spring is connected to the first spring receiving portion. positioning is controlled by a second bent part, and a third bent part is formed at a plurality of locations on the periphery of the hole formed in the center of the metal fitting, extending into the recess and fitting into the inner wall of the recess; A master device characterized in that a peripheral edge of the hole of the metal fitting excluding the third bent portion is used as a second spring receiving portion, and the second spring receiving portion receives one end of the compression spring. Cylinder piston spring holder.