JP2011169369A - Coil spring, fluid pressure booster using the same, and brake device having the fluid pressure booster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil spring capable of suppressing inclination in the radial direction when being deflected in the compressive direction. <P>SOLUTION: The coil spring 24 is wound by the predetermined number of turns. In the coil spring 24, a closely tight part between a first turn and a second turn is set to be 0.5 turn or substantially 0.5 turn while the preset compressive set load F is imparted and the coil spring is set in a compressive state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coil used in various devices such as a fluid pressure booster, such as a negative pressure booster or a hydraulic pressure booster, which boosts and outputs an input applied to an input means using a fluid pressure. TECHNICAL FIELD The present invention relates to a technical field of a spring, a fluid pressure booster using the spring, and a brake device including the fluid pressure booster. In particular, it is possible to suppress radial inclination in a state where the spring is mounted with a predetermined compression set load. The present invention relates to the technical field of coil springs, fluid pressure boosters, and brake devices.

  In order to be able to obtain a large braking force even with a small pedal depression force, an automotive brake device has conventionally been provided with a fluid pressure booster that boosts the pedal depression force with a fluid pressure to generate a large output. Many brake devices are known. As one of such fluid pressure boosters, there is a negative pressure booster that boosts the pedal depression force with negative pressure to obtain a large output (see, for example, Patent Document 1).

  FIG. 4 is a cross-sectional view showing the negative pressure booster disclosed in Patent Document 1. As shown in FIG. In FIG. 4, 1 is a negative pressure booster, 2 is a front shell, 3 is a rear shell, 4 is a power piston member, 5 is a diaphragm, 6 is a power piston, 7 is a constant pressure chamber held at a negative pressure, and 8 is operated. Transformer chamber in which air is sometimes introduced; 9 is a valve body; 10 is an input shaft; 11 is a valve plunger; 12 is an air valve seat provided on the valve plunger 11; 13 is a negative pressure valve seat provided on the valve body 9; 14 is a control valve body, 15 is a control valve, 16, 17 and 18 are passage holes, 19 is an output shaft, 20 is a return spring that constantly biases the power piston 6 toward the non-operating position, 21 is a reaction disk, and 22 is The negative pressure introduction pipe and 23 are air introduction ports.

  Such a negative pressure booster 1 is used in a brake device as shown in FIG. In FIG. 5, 27 is a brake device, 28 is a brake pedal, 29 is a tandem master cylinder, 30 is a brake cylinder, and 31 is a wheel.

In the negative pressure booster 1, a negative pressure is always introduced into the constant pressure chamber 7 through a negative pressure introduction pipe 22. In the non-operating state of the negative pressure booster 1, the atmospheric valve seat 12 of the control valve 15 is in contact with the control valve body 14, and the control valve body 14 is slightly separated from the negative pressure valve seat 13. The control valve 15 is inactive. Therefore, the variable pressure chamber 8 is cut off from the atmosphere and communicated with the constant pressure chamber 7 via the passage holes 17 and 16, the gap between the control valve body 14 and the negative pressure valve seat 13 and the passage hole 18. Negative pressure is introduced into the variable pressure chamber 8.

When the brake pedal 28 is depressed from this non-operating state, the input shaft 10 strokes forward (leftward in FIG. 4), the control valve body 14 is seated on the negative pressure valve seat 13, and then the atmospheric valve seat 12 Leaves the control valve body 14. That is, the control valve 15 is switched. Thereby, the variable pressure chamber 8 is disconnected from the constant pressure chamber 7 and communicated with the atmosphere. Then, the atmosphere is introduced into the variable pressure chamber 8 from the atmosphere introduction port 23 through the gap between the control valve body 14 and the atmosphere valve seat 12 and the passage holes 16 and 17. Thereby, since a differential pressure is generated between the variable pressure chamber 8 and the constant pressure chamber 7, the power piston 6 including the power piston member 4 and the diaphragm 5 moves forward (moves to the left) to generate an output. This output is transmitted to a piston (not shown) of the tandem master cylinder 29 via the valve body 9, the reaction disk 21 and the output shaft 19. Then, the tandem master cylinder 29 is operated to generate a brake pressure, and the brake cylinder 30 is operated by this brake pressure to generate a braking force, so that the wheels 31 are braked.

  Since the output shaft 19 presses the reaction disc 21 by the reaction force caused by the brake pressure of the tandem master cylinder 29, the reaction disc 21 is pinched between the valve body 9 and the output shaft 19 and elastically deforms, and the valve plunger 11 Abut. Then, the force generated by the elastic deformation of the reaction disk 21 is transmitted as a reaction force to the brake pedal 28 via the valve plunger 11 and the input shaft 10.

  As the pressure in the variable pressure chamber 8 increases, the output of the power piston 6 increases and the valve body 9 further advances, so that the control valve body 14 contacts the atmospheric valve seat 12 while holding the seat with the negative pressure valve seat 13. Touch. As a result, no further air is introduced into the variable pressure chamber 8, and the pressure in the variable pressure chamber 8 becomes a pressure corresponding to the input applied to the input shaft 10 (force related to the pedal effort). The output of the power piston 6 at this time is a large output obtained by boosting the pedal depression force, and as a result, the tandem master cylinder 29 generates a brake pressure corresponding to the input of the input shaft 10. Therefore, the braking force of the brake applied to the wheel 31 is a large braking force obtained by multiplying the pedal depression force.

When the brake pedal 28 is released, both the input shaft 10 and the valve plunger 11 are retracted, and the control valve body 14 is separated from the negative pressure valve seat 13. Then, the variable pressure chamber 8 communicates with the constant pressure chamber 7, and the air introduced into the variable pressure chamber 8 passes through the passage holes 17 and 16, the gap between the control valve body 14 and the negative pressure valve seat 13, the passage hole 18 and the constant pressure chamber 7. And is discharged from the negative pressure introduction pipe 22. As a result, the pressure in the variable pressure chamber 8 decreases, and the spring force of the return spring 20 causes the valve body 9, the power piston 6, and the output shaft 19 to move backward to the inoperative position, and the control valve 15 is inoperative as shown in the figure. It becomes a state. As a result, the tandem master cylinder 29 and the brake cylinder 30 are also deactivated, and the brake is released.
Thus, the negative pressure booster 1 can obtain a large output with a small pedal effort.

  Incidentally, a coil spring is used for the return spring 20 of the negative pressure booster 1. As shown in FIGS. 6A and 6B, the coil spring 24 is formed from a spring wire having a constant wire diameter and wound in a coil shape with a predetermined number of turns. The coil spring 24 has both end winding portions 25 (FIG. 6A shows only one end winding portion 25, and the other end winding portion is not shown) and both end winding ends. The coil portion 26 is provided continuously between the end turn portions 25. The end turn portion 25 is wound in an arc shape with a predetermined coil diameter in a plane orthogonal to the longitudinal direction of the coil spring 24 (vertical direction in FIG. 6A). Since the end winding portion on the other end side and the portion of the coil portion 26 continuing to this are the same as those on the one end side when FIG. 6A is turned upside down, this conventional coil spring will be described hereinafter. 24 and the coil spring 24 of the present invention will be described with respect to the end winding portion 25 on one end side and the portion of the coil portion 26 continuous thereto, and the other end side will be omitted.

  The coil portion 26 is provided continuously from the predetermined position α before reaching the first winding of the end winding portion 25 to the end winding portion 25, and is formed so as to extend in the longitudinal direction as the spring wire is wound. Yes. In that case, the pitch of the coil portion 26, which is the distance traveled in the longitudinal direction per turn of the spring wire, is constant at the pitch p. That is, as shown in FIGS. 6A and 6C, the inclination angle θ when the coil portion 26 is viewed from the side is set to be constant from one end side to the other end side of the coil portion 26.

The coil spring 24 is formed in contact with the end 25a of the end winding portion 25 in the longitudinal direction of the coil spring 24 as shown in FIG. 6A when the spring wire is wound once in a free state. Alternatively, the coil spring 24 is formed so as to be separated from the end 25a in the longitudinal direction.

  Incidentally, in the negative pressure booster 1, the coil spring 24 is rarely used in the free state shown in FIG. 6A, and is used in a compressed state to which a preset compression set load F is applied. There are many cases. Thus, when the coil spring 24 is set in a compressed state and used, a part 26 a of two turns of the spring wire in the coil portion 26 can come into contact with the end turn portion 25 in the longitudinal direction of the coil spring 24.

  A compression state in which the compression set load F is applied and the compression set state is set with the compression set load F applied thereto and the coil portion 26 is set in a compressed state so that a part of the coil portion 26 is in close contact with all of the end winding portions 25 without gaps. A coil spring 24 and a fluid pressure booster have been proposed in which the vibration of the coil spring 24 generated when an operating force is applied to the coil spring 24 is attenuated to suppress the generation of abnormal noise (Patent Document 2). reference). The reference numerals are used in correspondence with the above-described FIGS.

JP-A-57-107945. JP 2006-77904 A.

  However, in the coil spring 24 and the fluid pressure booster described in Patent Document 2, the coil spring 24 of the return spring 20 abuts and engages with the front shell 2 whose output side end is stationary via a separate member. At the same time, the input side end is in contact with and engaged with the movable valve body 9. For this reason, when the valve body 9 moves forward in the direction of compressing the return spring 20 during operation of the fluid pressure booster, when the coil spring 24 bends in the compression direction, the coil spring 24 does not bend straight in the longitudinal direction, There is a possibility of bending in an arbitrary radial direction. When the coil spring 24 is bent in a radial direction in this way, an uneven load is applied to the piston of the master cylinder 29 that is operated by the output of the fluid pressure booster, and the piston is difficult to slide smoothly in the cylinder. In addition to this, there is a risk of uneven wear of the piston and deterioration of the sealing performance of the seal between the piston and the cylinder.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coil spring capable of suppressing tilting in the radial direction when bending in the compression direction and a fluid pressure booster using the coil spring. And a brake device that includes this fluid pressure booster and can suppress uneven wear of the piston operated by the fluid pressure booster and deterioration of the sealing performance of the seal between the piston and the cylinder. is there.

  In order to solve the above-described problems, the coil spring of the present invention is a coil spring formed by winding with a predetermined number of turns, and is set in a compressed state by applying a preset compression set load F And the adhesion part of the 1st volume and the 2nd volume is characterized by being 0.5 volume or substantially 0.5 volume.

  In addition, the fluid pressure booster of the present invention includes at least a return spring that biases the piston toward the non-actuated position while the piston is actuated and output when the fluid pressure acts on the piston. In the fluid pressure booster, the return spring is the aforementioned coil spring of the present invention.

  Furthermore, the brake device of the present invention includes a brake pedal, a fluid pressure booster operated by the brake pedal, a master cylinder operated by an output of the fluid pressure booster, and a brake generated by the master cylinder. And a brake cylinder that generates a braking force by operating with pressure, and the fluid pressure booster is the fluid pressure booster of the present invention described above.

  According to the coil spring according to the present invention configured as described above, when a compression load is applied from a state in which a preset compression set load F is applied to the coil spring, the lateral load of the coil spring is relatively low. small. Therefore, when the coil spring is bent in the compression direction, it is possible to suppress the coil spring from being inclined and bent in an arbitrary radial direction of the coil.

  The fluid pressure booster and the brake device according to the present invention use the coil spring of the present invention described above. Therefore, according to the fluid pressure booster and the brake device according to the present invention, the coil spring can be prevented from being tilted and bent in an arbitrary radial direction of the coil, so that the output of the fluid pressure booster can be stabilized. It becomes possible. Then, by disposing the fluid pressure booster in the brake device, it is possible to suppress an uneven load from acting on the piston of the master cylinder of the brake device that is operated by the output of the fluid pressure booster. As a result, the piston of the master cylinder can slide in the cylinder more smoothly, and it is possible to suppress uneven wear of the piston of the master cylinder and deterioration of the sealing performance between the piston and the cylinder. As a result, the brake device can be stably operated over a long period of time.

The compression spring of the example of embodiment of the coil spring which concerns on this invention is shown in the state provided, (a) is the front view which shows partially, (b) is a base and the 1st volume in (a). The figure which looked at the closely_contact | adhered part (state which contact | adhered closely) from the upper part, (c) looked at the part (state which contact | adhered closely) from which the 1st volume and the 2nd volume contact | adhered in (a) from the upper part. It is a figure. BRIEF DESCRIPTION OF THE DRAWINGS The test apparatus about the coil spring which concerns on this invention is shown typically, (a) is a general view, (b) is a bottom view of the table which took the cover member, (c) is a figure which shows each load sensor. It is a figure which shows a test result. It is sectional drawing which shows the negative pressure booster currently disclosed by patent document 1. FIG. It is a figure which shows typically an example of the conventional common brake device. The coil spring used for the conventional negative pressure booster shown in FIG. 4 is shown, (a) is a partial front view partially showing, (b) is a bottom view, and (c) is a spring inclination angle of the coil part. FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 shows a state in which a compression set load of an embodiment of a coil spring according to the present invention is applied, (a) is a front view partially showing, (b) shows a pedestal and 1 in (a). The figure which looked at the part (state in which it adhered closely) from the upper part which stuck the winding, and (c) is the part (the state in which it closely adhered) where the 1st volume and the 2nd volume adhered in (a). It is the figure which looked at from the upper part. In the following description, the same components as those in the above-described conventional example are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 1 (a), the coil spring 24 of this example is formed from a spring wire having a constant wire diameter, and the end winding portions 25 at both ends in the vertical direction (FIG. 1 (a) has a seat on one end side. Only the winding part 25 is illustrated) and a coil part 26 provided continuously between the end winding parts 25 at both ends.

  And the coil spring 24 of this example is in the state where the preset compression set load F is applied, as shown in FIG. 1B, the first winding of the coil spring 24 (including the end winding portion 25). Of these, all of the 0.35 to 0.5 winding portions 24 a are in close contact with the pedestal 32. Similarly, in the state where the compression set load F is applied, as shown in FIG. 1C, all of the second or second winding portion 24b of the coil spring 24 is one winding. Close contact with eyes. The same applies to the other end side of the coil spring 24.

When the coil spring 24 of this example configured as described above is set in a compressed state in which the compression set load F is applied as the litter spring 20 to the negative pressure booster 1 in which the coil spring 24 is used, the litter spring 20 is similarly set. Of the first roll on one end side, all of the 0.35 to 0.5 winding portions are in close contact with the front shell 2 or another flat plate member that is in close contact with the front shell 2 and the other end of the litter spring 20 Of the first roll on the side, all of the 0.5 or substantially 0.5 winding portion is in close contact with the valve body 9 or another flat plate member that is in close contact with the valve body 9.

  According to the coil spring 24 of this example, when a compression load is applied from a state in which a preset compression set load F is applied to the coil spring 24, the lateral load of the coil spring 24 (the coil of the coil spring 24) The radial load of the portion 26 is relatively small. Therefore, when the coil spring 24 is bent in the compression direction, the coil spring 24 can be prevented from being inclined and bent in an arbitrary radial direction of the coil portion 26.

  Moreover, since it can suppress that the coil spring 24 inclines in the arbitrary radial directions of the coil part 26 and bends, when the coil spring 24 of this example is used for the negative pressure booster 1, the negative pressure booster 1 Can be stabilized. Then, by disposing the negative pressure booster 1 in the brake device 27, it is possible to suppress an uneven load from acting on the piston of the tandem master cylinder 29 of the brake device 27 that is operated by the output of the negative pressure booster 1. it can. As a result, the piston of the tandem master cylinder 29 can slide more smoothly in the cylinder, and the uneven wear of the piston of the tandem master cylinder 29 and the deterioration of the sealing performance between the piston and the cylinder can be suppressed. It becomes possible. As a result, the brake device 1 can be stably operated over a long period of time.

By the way, it was examined by a test that the coil spring 24 of this example is restrained from being inclined and bent in an arbitrary radial direction of the coil portion 26.
FIG. 2 is a diagram schematically showing a test apparatus used for this test.
As shown in FIG. 2, the test apparatus 33 includes a table 34 that supports one end of the coil spring 24, a support bracket 35 that supports the other end of the coil spring 24, and a load applied to the support bracket 35 in the longitudinal direction of the coil spring 24. And a sensor mounting member 37 disposed below the table 34.

  The table 34 includes a table main body 34a, a large number of balls 34b that are rotatably disposed on the table main body 34a, and a lid member 34c that is disposed so as to be relatively movable on the table main body 34a and contacts the large number of balls 34b. And have.

The sensor mounting member 37 includes three longitudinal load sensors 38 disposed below the table 34 so as to contact the lid member 34c, and a side of the table 34 so as to contact the table main body 34. And three lateral load sensors 39 disposed on the side. When the load is applied from the load applying device 36 to the coil spring 24 through the support bracket 35 in the longitudinal direction of the coil spring 24 as indicated by the arrow, the longitudinal load sensor 38 measures the load in the longitudinal direction of the coil spring 24. To detect. Further, the lateral load sensor 39 is configured such that when a load is applied from the load applying device 36 to the coil spring 24 through the support bracket 35 in the longitudinal direction of the coil spring 24 as indicated by an arrow, Detects lateral load in the radial direction.

Four types of test pieces of the coil spring 24 were used. That is, each of the four types of coil springs 24 is made of SWPC MEMS, and the wire diameter is (4.0 ± 0.03).
mm, the diameter of the coil portion 26 (the length between the centers of the wires) is 59.7 mm, and the winding direction of the coil portion 26 is right-handed. The first coil spring 24 has a spring constant of 2.78 N / mm.
The free length is 157.3 mm, the total number of turns of the coil portion 26 is 5.86, and the compression set load F is 205.2N. Further, the second coil spring 24 has a spring constant of 2.79 N / mm, a free length of 156.6 mm, a total number of turns of the coil portion 26 of 5.87, and a compression set load F of 203.9 N. Further, the third coil spring 24 has a spring constant of 3.07 N / mm, a free length of 151.0 mm, a total number of turns of the coil portion 26 of 5.85, and a compression set load F of 206.9 N. Further, the fourth coil spring 24 has a spring constant of 3.00 N / mm, a free length of 153.2 mm, a total number of turns of the coil portion 26 of 5.85, and a compression set load F of 208.7 N. Here, the compression set load F differs depending on each coil spring 24. The set stroke of the coil spring 24 used in the negative pressure booster 1 is the set stroke of each coil spring 24 (stroke compressed from the free length). Since it is the same (in this test, the set stroke is about 78.6 mm), it differs depending on the difference in spring constant. Note that the stroke and load of the coil spring 24 are proportional to each other in the elastic region.

In the test, the coil spring 24 is set in the test apparatus 33 between the table main body 34a and the support bracket 35 as shown in FIG. At this time, the outputs of the longitudinal load sensors 38 and the lateral load sensors are adjusted to 0, respectively. Then, a load is applied to the coil spring 24 by the load applying device 36 to temporarily compress the coil spring 24 to its full stroke. Next, the coil spring 24 is returned to the free length. From this state, a lateral load is detected by the lateral load sensor 39 while applying a load to the coil spring 24 by the load applying device 36 and increasing the applied load. The set strokes of the first to fourth coil springs 24 are both about 78.6 mm. In the first to fourth coil springs 24, the close contact portion between the first and second windings is 0.26 windings and 0.2 mm, respectively. 35 turns, 0.45 turns, and 0.54 turns.

As shown in Fig. 1 (c), a thickness gauge (JIS standard) with a thickness of 0.1 mm is inserted between the first and second rolls to detect the contact between the first and second rolls. Then, the coil portion at a position where the thickness gauge cannot be sandwiched between the first and second rolls was marked, and the amount of winding from the end 25a of the coil spring 24 to the position of this mark was measured. . In addition, for the detection of the contact portion between the base 32 and the first roll, the amount of winding was measured in the same manner using a thickness gauge of 0.1 mm as shown in FIG. The detected longitudinal load was the average value of the three longitudinal load sensors 38, and the detected lateral load was the maximum value of the three lateral load sensors 38.

The test results are shown in FIG. As shown in FIG. 3, when the contact portion is 0.26 winding and 0.35 winding, the lateral load becomes maximum in the stroke region of the coil spring 24 of the negative pressure booster 1 and the absolute value of the maximum lateral load is absolute. The value is also large. On the other hand, with 0.45 winding and 0.54 winding, the lateral load becomes maximum before the stroke region of the negative pressure booster 1, and the absolute value of the maximum lateral load is relatively small. In addition, in the stroke region (stroke of the output shaft 19) of the negative pressure booster 1 in which the tandem master cylinder 29 generates the brake pressure, the lateral load becomes maximum at 0.26 and 0.35 turns. , 0.45 winding and 0.54 winding, the lateral load becomes considerably small. Accordingly, if the tight contact portion between the first and second windings of the coil spring 24 is applied with a compression set load F of 0.5 or approximately 0.5, the operation of the negative pressure booster 1 is performed. At that time, it was confirmed that the radial deflection of the return spring 20 can be effectively suppressed.

  The coil spring 24 of this example, the negative pressure booster 1 in which the coil spring 24 is used, and the brake device 27 including the negative pressure booster 1, and other configurations and other functions and effects are described above with reference to FIGS. 6 is substantially the same as the conventional coil spring 24, the conventional negative pressure booster 1, and the conventional brake device 27 shown in FIG.

  In the above example, the coil spring of the present invention is used for the return spring 20 of the negative pressure booster 1. However, for example, a hydraulic booster used in a brake system or the like, a booster using compressed air, or the like. Any coil spring can be used as long as it is a coil spring that is attached to the apparatus with a preset compression set load F applied thereto and to which an external operating force can be applied. Can also be applied. In short, the present invention is not limited to the above-described examples, and various design changes can be made within the scope of the matters described in the claims.

The coil spring according to the present invention can be suitably used as a coil spring that is mounted on the apparatus in a state where a preset compression set load F is applied and an external operating force is applied.
Moreover, the fluid pressure booster and the brake device according to the present invention can be suitably used for a brake device for a brake device and a brake device for obtaining a braking force by boosting an operation force of an operator.

DESCRIPTION OF SYMBOLS 1 ... Negative pressure booster, 6 ... Power piston, 10 ... Input shaft, 15 ... Control valve, 19 ... Output shaft, 20 ... Return spring, 24 ... Coil spring, 24a ... Close_contact | adherence part of a base and 1st volume, 24b: Close contact portion between the first and first rolls, 25a ... end, 27 ... brake device, 28 ... brake pedal, 29 ... tandem master cylinder, 30 ... brake cylinder, 33 ... test device

Claims (3)

In the coil spring formed by winding with a predetermined number of turns,
The coil characterized in that the contact portion between the first and second rolls is 0.5 or approximately 0.5 turns in a state where a preset compression set load is applied and the compression set is applied. spring. In the fluid pressure booster comprising at least a return spring that urges the piston in the direction of the non-actuated position while the piston is actuated and outputted by the fluid pressure acting on the piston,
The fluid pressure booster according to claim 1, wherein the return spring is a coil spring according to claim 1. A brake pedal, a fluid pressure booster operated by the brake pedal, a master cylinder operated by an output of the fluid pressure booster, and a brake pressure generated by the brake pressure generated by the master cylinder And at least a brake cylinder
The brake device according to claim 2, wherein the fluid pressure booster is the fluid pressure booster according to claim 2.

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