JP2000001163A - Fluidless brake operating stroke generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a brake operating feel equivalent to the hydraulic brake unit using fluid with the fluidless brake unit without using fluid, in the fluidless brake operating stroke generator, which is used in a fluidless brake unit to control the vehicle corresponding to brake operation without fluid and generates an operating stroke according to the braking force in the brake operating member. SOLUTION: A mechanism is provided that gives the relationship between the control force and operating stroke of a brake pedal 10 to the hysteresis characteristics without use of fluid. This mechanism may contain a hysteresis elastic body 42 made up with a material, with its length elastically changeable according to the load received, and the relationship between load and length having hysteresis characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidless type brake operation stroke generator used in a fluidless type brake device for braking a vehicle in accordance with a brake operation without using fluid.

[0002]

2. Description of the Related Art There are two types of brake devices: a fluid type in which fluid is used to brake wheels according to a brake operation and a fluidless type in which fluid is not used. As is well known, the fluid type is a hydraulic brake device that mechanically operates a brake via the fluid by an operation force of a driver. A conventional example of a fluidless type is described in German Patent Publication DE19615186C1. this is,
(a) a brake operating member, (b) a fluidless type brake operating stroke generator for generating an operating stroke corresponding to the operating force of the brake operating member to the brake operating member without using fluid, and (c) a motor. An electric brake that suppresses the rotation of wheels by a driving force, and (d) a controller that controls a motor according to an operation force or an operation stroke to control the electric brake.

[0003]

SUMMARY OF THE INVENTION In a fluid type brake device, fluid exists between the brake operating member and the brake. This fluid characteristic has a great influence on the brake operation feeling. Specifically, the so-called hysteresis characteristic in which the operation stroke corresponding to the same operation force is different between the increasing stroke and the decreasing stroke of the operating force is referred to as the operating force and the operating force. This is given to the brake operation characteristics that are related to the stroke.

On the other hand, in the fluidless type brake device described in the above publication, no fluid exists between the brake operating member and the brake. for that reason,
The brake operation feeling is different from that of the fluid type brake device, and a driver who is used to the fluid type brake device may feel uncomfortable when using the fluidless type brake device.

[0005] Against this background, the present invention provides:
It is an object of the present invention to provide a fluid-less brake operation stroke generator capable of realizing the same brake operation feeling as a fluid-type brake device without using fluid in the fluid-less brake device. The following aspects are obtained.
Each mode is described in the same manner as in the claims, divided into sections, each section is numbered, and described in the form of citing the numbers of other sections as necessary. This is to facilitate an understanding of some of the technical features and combinations thereof described herein,
The technical features and combinations thereof described in this specification should not be construed as being limited to the following embodiments.

(1) Used in a fluidless type brake device for braking a vehicle in response to a brake operation without using fluid, an operation stroke corresponding to the operating force of the brake operating member without using fluid is applied to the brake operating member. In the fluidless type brake operation stroke generating device to be generated, a hysteresis characteristic imparting mechanism for imparting a hysteresis characteristic to the brake operation characteristic which is a relationship between the operation force and the operation stroke without using fluid is provided. Fluidless type brake operation stroke generator [Claim 1]. According to this device,
Since the hysteresis characteristic is given to the relationship between the operation force and the operation stroke without using fluid, a brake operation feeling equivalent to that of the fluid type brake device can be realized without using fluid in the fluidless type brake device. (2) The hysteresis characteristic imparting mechanism includes a hysteresis elastic body made of a material having a hysteresis characteristic in which the length changes elastically according to the received force and the relationship between the force and the length, and the hysteresis The fluidless type brake operation stroke generator according to claim 1, wherein a hysteresis characteristic is imparted to the brake operation characteristic by an elastic body. According to this device, the hysteresis characteristic can be given to the brake operation characteristic by utilizing the mechanical property of the material constituting the hysteresis elastic body, so that the structure of the hysteresis characteristic imparting mechanism does not need to be complicated. (3) The fluidless type brake operation stroke generator according to (2), wherein the material includes at least one of rubber and urethane foam. (4) Further, the normal elastic body made of a material whose length is elastically changed according to the received force and whose relationship between the force and the length does not substantially have the hysteresis characteristic is the hysteresis elastic body. (2) or (3) provided in series with
A fluidless type brake operation stroke generating device according to claim [Claim 3]. According to this device, the requirement to be imposed on the hysteresis elastic body is reduced as compared with the case where both the generation of the operation stroke and the provision of the hysteresis characteristic are performed only with the hysteresis elastic body, and the selection of the hysteresis elastic body is reduced. The degree of freedom is improved, and the degree of freedom in selecting the brake operation characteristics is improved. (5) The fluidless brake operation stroke generator according to the above mode (4), wherein the hysteresis elastic body is softer than the normal elastic body. When the hysteresis elastic body is designed so that the brake operation characteristic has the hysteresis characteristic in the entire range in which the operation force can be changed, the dimensional change amount of the hysteresis elastic body becomes large, and the operation stroke generating device becomes large. there is a possibility. On the other hand, in the operation stroke generating device described in this section, the brake operation characteristic has a hysteresis characteristic at least in a region where the operation force is small, that is, in a normal region, but not in the entire region where the operation force can be changed. It becomes possible to. Therefore, according to this operation stroke generating device, it is possible to avoid an increase in the size of the operation stroke generating device due to an increase in the dimensional change amount of the hysteresis elastic body. Further, according to the operation stroke generating device, it is possible to realize a non-linear characteristic that the brake operation feeling is soft in a region where the operation force is small and hard in a region where the operation force is large. (6) Further, after the elastic deformation amount of the hysteresis elastic body has increased to a set value, an operation force action preventing mechanism for preventing the operation force from acting on the hysteresis elastic body is included (5). Fluidless type brake operation stroke generator. According to this device, an excessive load is not applied to the hysteresis elastic body. (7) The hysteresis characteristic imparting mechanism includes a sliding resistance imparting mechanism that imparts sliding resistance to the brake operating member so that the magnitude is different between an increasing stroke and a decreasing stroke of the operating stroke (1). A fluidless type brake operation stroke generator according to any one of the above items (6) to (6). (8) The sliding resistance imparting mechanism (a) is caused to directly or indirectly generate a sliding resistance in the brake operating member by being brought into contact with the brake operating member or an interlocking member mechanically interlocked with the brake operating member. (B) a sliding resistance generator
The fluid according to claim 7, further comprising a contact pressure control mechanism for making the contact pressure at which the sliding resistance generator contacts the brake operating member or the interlocking member different between an increasing stroke and a decreasing stroke of the operating stroke. Less-type brake operation stroke generator. (9) A sliding resistance that directly or indirectly generates a sliding resistance in the brake operating member by being brought into contact with the brake operating member or an interlocking member mechanically interlocked with the brake operating member. A part of the generator, in which the sliding resistance generator is brought into contact with the brake operating member or the interlocking member, is different from each other in the increasing stroke and the decreasing stroke of the operation stroke, and the sliding resistance generator is in the operating stroke. The sliding resistance generator includes a first portion that is brought into contact with the brake operating member or the interlocking member in the increasing stroke and a second portion that is brought into contact in the decreasing stroke of the operating stroke. ). The fluid-less type brake operation stroke generating device according to the above item. (10) A sliding resistance that directly or indirectly generates a sliding resistance in the brake operating member by being brought into contact with the brake operating member or an interlocking member that is mechanically interlocked with the brake operating member. A part of the generator, in which the sliding resistance generator is brought into contact with the brake operating member or the interlocking member, is different from each other in the increasing stroke and the decreasing stroke of the operation stroke, and the sliding resistance generator is in the operating stroke. Including a sliding resistance generator in which the area of the first portion contacted with the brake operating member or the interlocking member in the increasing stroke and the area of the second portion contacted in the decreasing stroke of the operating stroke are different from each other
A fluidless type brake operation stroke generating device according to the above mode (7). (11) the hysteresis characteristic imparting mechanism, (a) an air chamber whose volume changes according to the operation stroke, (b) is provided between the air chamber and the atmosphere, between the air chamber and the atmosphere A flow resistance applying mechanism for applying a flow resistance to the air flowing therethrough so that at least one of the size and the direction is different from each other in the increasing stroke and the decreasing stroke of the operation stroke. (1) to (10). Fluidless type brake operation stroke generating device according to the present invention. (12) The fluid dress according to any one of (1) to (11), wherein the hysteresis characteristic is such that the operating stroke corresponding to the same operating force is smaller in the increasing stroke of the operating force than in the decreasing stroke. Type brake operation stroke generator. (13) The first elastic body, wherein the hysteresis characteristic imparting mechanism is elastically deformed in response to a received force and imparts a hysteresis characteristic to the brake operation characteristic based on the elastic deformation. Including those with
A fluidless type brake operation stroke generator according to any one of (1) to (12) [Claim 5]. Said (1)
The operation stroke generating device according to the item is implemented in a mode in which the hysteresis characteristic imparting mechanism includes an elastic body that is elastically deformed in response to a received force and that imparts a hysteresis characteristic to the brake operation characteristic based on the elastic deformation. be able to. In this aspect, unless the behavior (for example, the temporal change of the shape of the elastic body) when the elastic body is elastically deformed by the operation force is the same between a certain brake operation and another brake operation, the same operation is performed. Operation strokes corresponding to force may be different from each other. The hysteresis characteristic imparted to the brake operation characteristics by the elastic body may depend on the elastic deformation behavior of the elastic body. In such a case, it is necessary to stabilize the elastic deformation behavior of the elastic body in order to stabilize the hysteresis characteristics and thereby stabilize the brake operation feeling. On the other hand, in the operation stroke generating device described in this section, the elastic body that imparts the hysteresis characteristic to the brake operation characteristic is provided with a portion that is easily elastically deformed. Therefore, when a force is applied to the elastic body, the elastic body is always elastically deformed with the same behavior, such as elastically bending, bending, buckling, bending, etc., using the same site as the deformation start site. The elastic deformation behavior is stabilized. Therefore, according to this operation stroke generating device, as described above, even when the hysteresis characteristic given to the brake operation characteristic by the elastic body depends on the elastic deformation behavior of the elastic body, the hysteresis characteristic is stabilized. As a result, the braking operation feeling is also stabilized. In this operation stroke generating device, the “elastic body” is made of a material having a hysteresis characteristic. As a result, the elastic body itself has a hysteresis characteristic,
Therefore, it is possible to adopt a form in which the hysteresis characteristic is directly added to the brake operation characteristic by the elastic deformation of the elastic body. The "elastic body" itself does not have hysteresis characteristics, but due to the elastic deformation of the elastic body, the sliding resistance between the member arranged to be able to contact the elastic body and the elastic body changes. In addition, a hysteresis characteristic may be provided to the brake operation characteristic by a change in the sliding resistance. (14) The first elastic body has a shape extending along one axis, receives the operating force in the axial direction, and has a sectional shape thereof at a set position on the axis. The fluidless type brake operation stroke generating device according to the mode (13), wherein a portion which is easily elastically deformed by being reduced at the peripheral position is set. (15) The first elastic body has a shape extending along one axis and receives the operating force in the axial direction, and the elastic modulus of a material constituting itself is set on the axis. The fluidless type brake operation stroke generating device according to the mode (13), wherein a portion which is easily elastically deformed is set by making the position smaller than its peripheral position. (16) further including two members that are moved toward and away from each other in accordance with an increase and decrease in the operation force, and a cylindrical member having an inner peripheral surface fitted to at least one of the two members, and The first elastic body is disposed between the two members at a position where the first elastic body can come into contact with the inner peripheral surface of the cylindrical member, and the first elastic body is elastically deformed by elastic deformation of the first elastic body due to approach / separation of the two members The body is brought into contact with the inner peripheral surface of the cylindrical member, and the sliding resistance between the first elastic body and the cylindrical member at that time imparts hysteresis characteristics to the brake operation characteristics (13) to (15). 20. The fluidless type brake operation stroke generator according to any one of the above items. (17) The fluidless type according to (16), wherein the first elastic body extends in the axial direction of the first elastic body, and at least one of both ends thereof is more easily elastically deformed in the other part. Brake operation stroke generator. (18) Further, two members which are respectively approached and separated from each other in accordance with increase and decrease of the operation force,
A stroke end of the brake operating member is defined by their contact with each other;
A force is provided on at least one of the members, and after the two members approach each other and the distance between the two members reaches a set distance, a force is applied to the two members to prevent the two members from approaching each other. Including a second elastic body
A fluidless type brake operation stroke generator according to any one of (1) to (17) [Claim 6]. Said (1)
The operation stroke generating device described in the paragraph is a two-member that is moved toward and away from each other in accordance with an increase and a decrease in the operation force, and the stroke end of the brake operation member is defined by abutting them. Can be implemented. In this embodiment, unless the two members approach each other at all when they try to contact each other,
At the moment when the brake operating member reaches the stroke end, the operational feeling of the brake operating member suddenly becomes hard. On the other hand, in the operation stroke generating device described in this section,
When the two members try to contact each other, the two members are prevented from approaching each other. Therefore, according to this operation stroke generating device, the operation feeling of the brake operation member gradually becomes harder as the brake operation member approaches the stroke end, so that a good brake operation feeling is realized.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a fluidless type brake operation stroke generator (hereinafter, referred to as a first embodiment) of the present invention.
FIG. 2 shows a fluid-less type brake device (hereinafter, simply referred to as “brake device”) including an “operation stroke generator”, and FIG. 2 shows the operation stroke generator in an enlarged manner. .

The brake device is mounted on a four-wheeled vehicle equipped with an engine, front left and right wheels FL and FR, and rear left and right wheels RL and RR. As shown in FIG.
A brake pedal 10 is provided as a brake operation member. The base end of the brake pedal 10 is attached to the vehicle body so as to be rotatable around a rotation axis extending in the left-right direction of the vehicle. 10 is pivoted about its pivot axis. One end of a rod 18 extending in the vehicle front-rear direction is rotatably connected to an intermediate portion of the brake pedal 10 via a clevis 16. An operating stroke generator 20 is linked to the other end of the rod 18.

As shown in FIG. 2, the operation stroke generator 20 is disposed in an engine room 22. The operating stroke generating device 20 includes a cylindrical housing 24 having a step with a bottom, and the housing 24 is attached to a dash panel 30 of a vehicle body at a flange 26 formed at an opening thereof. A piston 32 is fitted to the housing 24 so as to be slidable in the axial direction. The other end of the rod 18 is linked to one of the two ends of the piston 32 which is located on the opening side of the housing 24. I have. The piston 32 and the rod 18 are in contact with each other via spherical surfaces complementary to each other, so that relative movement in the axial direction is prevented, while relative rotation is allowed.

The housing 24 further includes an intermediate member 34.
Are also slidably fitted in the axial direction. The intermediate member 34 is coaxial with the piston 32. The piston 32 is accessible to the intermediate member 34, and the limit of the access is limited to a stopper 36 formed on the intermediate member 34 and the piston 3.
It is defined by the contact with No. 2. Further, the separation limit between the piston 32 and the intermediate member 34 is
4 and a stopper 40 fixed to the distal end of the piston 32. Further, a cylindrical hysteresis elastic body 42 is disposed over the piston 32 and the intermediate member 34. This hysteresis elastic body 42
2 and are arranged coaxially with the intermediate member 34 so as to overlap therewith. The hysteresis elastic body 42 can be mainly composed of rubber or mainly composed of urethane foam.

The intermediate member 34 is accessible to the bottom (the left end in the figure) of the housing 24, and its access limit is intermediate with a stopper 48 formed integrally with a plug 46 for closing the bottom of the housing 24. It is defined by the contact with the member 34. And, those intermediate members 34
A coil spring 52 made of steel, which is usually an elastic body, is provided between the housing 52 and the bottom of the housing 24. The hysteresis elastic body 42 and the spring 52 are connected in series between the piston 32 and the bottom of the housing 24 via the intermediate member 34.

[0013] FIG. 3 shows the relationship between elastic properties or axial input load f _in the axial compression length S ₁ of the hysteresis elastic body 42 is represented by a graph. As is apparent from this graph, the hysteresis elastic body 42 is compressed length S ₁ is increased with increasing input load f _in, the same input load f
The value of the compression length S ₁ corresponding to the _in increased stroke of the input load f _in (indicated by the solid line graph) and reduced stroke (indicated by a broken line graph)
, And specifically, is shorter in the increasing stroke than in the decreasing stroke. Thus, the elastic characteristic of the hysteresis elastic body 42 has a hysteresis characteristic.

[0014] FIG. 4 shows the relationship between elastic properties or axial input load f _in the axial compression length S ₂ of the spring 52 is represented by a graph. As is apparent from this graph, the spring 52, similar to the hysteresis elastic body 42, the compression length S ₂ increases with increasing input load f _in. However, unlike the hysteresis elastic body 42, the same input load f value of the compression length S ₂ corresponding to _in the input load f _in
The increase stroke and the decrease stroke coincide with each other. Thus, the elastic characteristic of the spring 52 does not have a hysteresis characteristic.

[0015] FIG. 5 shows the relationship i.e. the brake operation characteristics of the operating force F _P of the brake pedal 10 and the operating stroke S _P of the operating stroke generator 20 is represented by a graph. This shows that the elastic characteristics of the hysteresis elastic body 42 and the elastic characteristics of the spring 52 are combined.

As shown in FIG. 2, the accessible distance L ₁ between the piston 32 and the intermediate member 34 is shorter than the accessible distance L ₂ between the intermediate member 34 and the bottom of the housing 24. Further, the hysteresis elastic body 42 is softer than the spring 52. Hysteresis elastic body 42
Is set smaller than the spring constant of the spring 52. Therefore, at the time of increase of the operating force F _P,
Disappeared in the approaching distance earlier than approaching distance L ₂ is more of L _1, and, before disappearance of accessible distances L _1, both the hysteresis elastic member 42 and the spring 52 will function as an elastic body, disappears Thereafter, only the spring 52 functions as an elastic body.

Therefore, as shown in FIG. 5, the brake operation characteristics are in the region where the operation force _FP is small (the approachable distance L
₁ before extinction) At exhibit a hysteresis characteristic, a large area (not show disappearance after) the hysteresis characteristic of the approach distance L _1. Incidentally, the specifications of the operation stroke generator 20, the brake operation characteristics are designed to exhibit hysteresis characteristics in the majority of normal use range of the operating force F _P.

The piston 32 is constantly urged by both the hysteresis elastic body 42 and the spring 52 in a direction away from the bottom of the housing 24, as shown in FIG.
As shown in (1), when the engaging portion 56 formed on the piston 32 comes into contact with the stopper 58 formed on the housing 24, the separation limit is defined. However, the engaging portion 56 and the stopper 58 are in contact with each other via a rubber annular cushioning member 60, so that when the piston 32 returns to the separation limit position, that is, the original position shown in the figure, The impact generated between the piston 32 and the housing 24 is reduced. Also, housing 2
4 has a communication hole 62 that constantly communicates a space formed between the engaging portion 56 and the stopper 58 with the atmosphere.

As shown in FIG. 1, the brake device further includes an electric brake 70 and an electric control device 72.

The electric brake 70 is provided for each wheel, and brakes each wheel without using fluid by using a motor 80 such as an ultrasonic motor or a DC motor as a drive source. Specifically, each electric brake 70 includes a disc,
The motor 80 includes a rotating body such as a brake drum that rotates with each wheel, and a friction material pressed against a friction surface of the rotating body such as a brake pad and a brake lining.
The rotation of each wheel is suppressed by pressing the frictional material against the rotating body by the driving force of.

The electric control device 72 includes a brake pedal 10
This is a device for electrically controlling the electric brake 70 in accordance with the operation of. Electric control device 72 as a detection section, an operation stroke sensor 84 for detecting the operating stroke S _P output brake pedal 10. Operating stroke sensor 84 is a rotary type for detecting the rotation angle of the brake pedal 10 as an operation stroke S _P. The electric control device 72 further includes an electronic control unit (hereinafter abbreviated as “ECU”) 86 as a control unit, a driver 88, and a battery 90 as a power supply. The ECU 86
The computer mainly includes a CPU, a ROM, and a RAM, and executes a brake control routine stored in the ROM while using the RAM by the CPU. vehicle deceleration G controls the electric brake 70 so as to generate in response to S _P. The ECU 86 is connected to the motor 80 via the driver 88,
8 supplies the electric power according to the signal received from the ECU 86 from the battery 90 to the motor 80.

FIG. 7 is a flowchart showing the brake control routine. This routine is repeatedly executed. In each execution, first, in step S1 (hereinafter simply referred to as “S1”; the same applies to other steps), the current operation stroke _SP is detected by the operation stroke sensor 84. Next, in S2, the detected operating stroke S target braking force to be generated on each wheel in order to generate the vehicle deceleration G corresponding to _P F _B ^* is determined. This determination is made in consideration of the distribution before and after the ideal braking force. Then, in S3, the motor 80 of the electric brake 70 of each wheel is driven in order to realize the determined target braking force F _B ^* of each wheel. This completes one execution of this routine.

As is apparent from the above description, in this embodiment, the hysteresis elastic body 52 constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a second embodiment of the present invention will be described. However, since this embodiment has many elements common to the first embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the first embodiment, the hysteresis characteristic imparting mechanism is provided inside the housing 24. In the present embodiment, as shown in FIG. 8, the selective damper 120 as the hysteresis characteristic imparting mechanism is provided. Is provided outside the housing 24. It is provided between the brake pedal 10 and the vehicle body.

FIG. 9 shows the selective damper 120 on an enlarged scale. The selective damper 120 is configured such that a piston 124 is slidably fitted to a bottomed cylindrical housing 122. An air seal 126 is brought into close contact with the housing 122 and the piston 124 so that the housing 122 and the piston 124 are substantially airtightly fitted. An air chamber 128 is formed in the housing 122 by the fitting. Piston 1
Reference numeral 24 denotes the brake pedal 10, and the housing 122 is rotatably connected to the vehicle body. As a result, the volume of the air chamber 128 increases when the brake pedal 10 is rotated clockwise in the figure from the original position shown in the figure, and is rotated counterclockwise from the rotated position. If it decreases.

As shown in FIG. 10 in which a part of the selective damper 120 is enlarged, the housing 122 has an air chamber 12.
8 is connected to the atmosphere, and a check valve 132 is provided in the middle of the air passage 130.
Is provided. The check valve 132 includes a ball 134 as a valve and a seat 136 on which the ball 134 is seated. This check valve 13
At 2, the ball 134 separates from the seat 136 if the pressure in the air chamber 128 is about to drop below atmospheric pressure, thereby allowing air to flow from the atmosphere into the air chamber 128 with a relatively low flow resistance. I do. On the other hand, if the pressure in the air chamber 128 is going to rise above the atmospheric pressure, the ball 134 will be seated on the seat 136. Sheet 1
36, a groove 138 is formed.
The air passage 130 is not completely closed even when the ball 134 is seated on the vehicle. Therefore, the air chamber 12
If the pressure of 8 is going to rise above the atmospheric pressure, the air is allowed to be discharged from the air chamber 128 to the atmosphere with a relatively large flow resistance.

As described above, in the present embodiment, the flow resistance becomes larger in the return stroke (operation force or operation stroke decreasing stroke) of the brake pedal 10 than in the stepping stroke (operation force or operation stroke increase stroke). Has been. On the other hand, the flow resistance of the air flowing through the air passage 130 acts as a force opposing the operation force of the brake pedal 10. Therefore, if the flow resistance increases in the return stroke, the force for rotating the brake pedal 10 toward the original position decreases as a result, even if the operating force is the same. Be longer. As described above, in the present embodiment, hysteresis characteristics are given to the brake operation characteristics by making the air flow resistance different between the step-in stroke and the return stroke.

In this embodiment, as shown in FIG. 8, a piston 32 and an intermediate member 34 are provided in a housing 24 as in the first embodiment. Also, between the intermediate member 34 and the bottom of the housing 24,
As in the first embodiment, a spring 52 is provided. However, between the piston 32 and the intermediate member 34, unlike the first embodiment, a plurality of disc springs 142 superposed in series and a coiled steel spring 144 are interposed via a spring retainer 146. They are in series with each other. The piston 32 can access the spring retainer 146 within a certain limit.
The spring 144 usually functions as an elastic body. Also,
The spring 144 is softer than the spring 52.

In the present embodiment, the hysteresis characteristic is given to the brake operation characteristic also by the sliding resistance between the plurality of disc springs 142. The sliding resistance causes a delay in the restoration of each disc spring 142, and as a result, a hysteresis characteristic is given. However, in the present embodiment, the effect is smaller than in the selective damper 120.

FIG. 11 shows a brake according to this embodiment.
Operating characteristics are shown. Operating force F _PIs small (contact area)
Possible distance L₁ Before the disappearance), two springs 5
2 and 144 both function as an elastic body,
(Accessible distance L₁ After the disappearance of the spring 52)
Only functions as an elastic body. Also, it is clear from the above description.
As you can see, the selective damper 12
0 does not function substantially and the air flow resistance is small.
In the return stroke, the selective damper 120 functions.
As a result, air flow resistance increases. Therefore, this implementation
In the embodiment, as shown in FIG.
(Shown in the graph)
Brake operation characteristics expressed by
In the return stroke (shown by the dashed line graph)
Power F_POperation stroke S corresponding to _PIs on the way
Longer brake operating characteristics,
As a result, the brake operation characteristics have hysteresis characteristics
It has become.

As is clear from the above description, in this embodiment, the selective damper 120 mainly constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a third embodiment of the present invention will be described. However, since this embodiment has many elements common to the second embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the second embodiment, a hysteresis characteristic is given to the brake operation characteristic by making the flow resistance of the air different between the step-in stroke and the return stroke. However, in the present embodiment, the same operation stroke S _P
The hysteresis characteristic is provided by making the magnitude of the sliding resistance of the piston 32 different from each other between the stepping stroke and the return stroke.

More specifically, as shown in FIG. 12, a rubber annular sliding resistance generator 150 is provided between the piston 32 and the housing 24. This sliding resistance generator 1
50 is an annular groove 15 formed on the outer peripheral surface of the piston 32.
2 is mounted inside. As is well known, the frictional resistance between the sliding resistance generator 150 and the housing 24 is larger than the dynamic frictional resistance in the static frictional resistance.

Therefore, in this embodiment, FIG.
As shown in the graph, during the stepping stroke (indicated by the solid line graph), the operation force F
The _P is small area, without increasing the operation stroke S _P,
After that, while increasing, return stroke (shown by a broken line graph)
In the operation force F _P A early return of brake operation in a large area, without reducing the operating stroke S _P, then decreases to. As a result, the operation stroke S _P corresponding to the same operating force F _P is shorter than in the return stroke in depression stroke, and brake operation characteristics becomes to have a hysteresis characteristic.

As is apparent from the above description, in this embodiment, the sliding resistance generator 150 constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a fourth embodiment of the present invention will be described. However, since this embodiment has many elements common to the second embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the second embodiment, a hysteresis characteristic is given to the brake operation characteristic by making the air flow resistance different between the step-in stroke and the return stroke, but in the present embodiment, the sliding of the piston 32 is performed. The hysteresis characteristics are provided by making the magnitude of the dynamic resistance different between the stepping stroke and the return stroke.

In the present embodiment, as shown in FIG. 14, a rubber annular sliding resistance generator 160 is provided between the piston 32 and the housing 24. The sliding resistance generator 160 is mounted in an annular groove 162 formed on the outer peripheral surface of the piston 32. As shown in FIG. 15, the groove 162 is formed such that the depth is larger on the right side in the figure and on the left side. The right portion of the groove 162 in the figure is a rear portion in the direction in which the piston 32 moves when the operating force or the operating stroke increases, while the left portion decreases the operating force or the operating stroke. At the rear in the direction in which the piston 32 moves.

In the stepping stroke, the piston 32 moves to the left with respect to the housing 24 with respect to the housing 24, as shown in FIG.
By being moved and pushed into the deep portion of the groove 162, it is pressed against the inner peripheral surface of the housing 24 with a relatively small amount of compression. In the stepping stroke, the sliding resistance generator 160 is brought into contact with the inner peripheral surface of the housing 24 with a relatively low contact pressure. On the other hand, in the return stroke, the piston 32 moves rightward in the figure with respect to the housing 24 as shown in FIG.
The sliding resistance generator 160 moves to a shallow portion of the groove 162 and is pushed into the groove, thereby being pressed against the inner peripheral surface of the housing 24 with a relatively large amount of compression. In the return stroke, the sliding resistance generator 160 is brought into contact with the inner peripheral surface of the housing 24 with a relatively high contact pressure.

The sliding resistance of the piston 32 also acts as a force opposing the operating force of the brake pedal 10, similarly to the air flow resistance. Further, as described above, the sliding resistance is also made larger in the return stroke than in the step-in stroke. Therefore, in the present embodiment, the operation stroke corresponding to the same operation force is smaller in the stepping stroke than in the return stroke. That is, in the present embodiment, the hysteresis characteristic is given to the brake operation characteristic by making the sliding resistance of the piston 32 different between the step-in stroke and the return stroke.

As is clear from the above description, in this embodiment, the sliding resistance generator 160 and the groove 162 cooperate with each other to constitute a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a fifth embodiment of the present invention will be described. However, since this embodiment has many elements common to the fourth embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the fourth embodiment, the hysteresis characteristic is given to the brake operation characteristic by making the pressure at which the sliding resistance generator 160 comes into contact with the housing 24 different between the step-in stroke and the return stroke. In this embodiment, hysteresis is obtained by making the friction coefficient of the surface of the first portion in contact with the piston during the stepping stroke and the friction coefficient of the surface of the second portion in contact with the return stroke different from each other. Properties are being provided.

Specifically, as shown in FIG. 16, an annular groove 180 is formed in a portion of the housing 24 where the piston 32 is fitted. Unlike the fourth embodiment, the depth of the groove 180 is constant in the axial direction of the piston 32. An annular sliding resistance generator 182 made of rubber is mounted in the groove 180. As shown in FIG. 17, the cross section of the sliding resistance generator 182 is symmetrical with respect to a plane perpendicular to the axis of the sliding resistance generator 182, and is in contact with the outer peripheral surface of the piston 32 at a convex surface. The shape has a portion 183. The shape having such a contact portion 183 is provided so that the portion of the surface of the sliding resistance generator 182 that contacts the piston 32 is different from each other between the step-in stroke and the return stroke. The surface of the sliding resistance generator 182 is virtually divided into two by the above-mentioned plane, and the friction coefficient of the surface is set to be lower in the first portion 184 on the right side than in the second portion 186 on the left side in the drawing. ing. Here, the first portion 184 is a rear portion of the sliding resistance generator 182 in a direction in which the piston 32 moves when the operating force or the operating stroke increases, while the second portion 18
Reference numeral 6 denotes a rear portion in a direction in which the piston 32 moves when the operation force or the operation stroke decreases.

In the step-in stroke, as shown in FIG. 18A, the sliding resistance generator 182 mainly comes into contact with the outer peripheral surface of the piston 32 at the first portion 184 having a low coefficient of friction. The sliding resistance of the piston 32 by the resistance generator 182 becomes relatively small. On the other hand, in the return stroke, as shown in FIG.
Is mainly located in the second portion 186 having a high coefficient of friction.
Therefore, the sliding resistance of the piston 32 by the sliding resistance generator 182 becomes relatively large. By making the sliding resistance different between the step-in stroke and the return stroke in this way, a hysteresis characteristic is given to the brake operation characteristic.

As is apparent from the above description, in this embodiment, the sliding resistance generator 182 constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a sixth embodiment of the present invention will be described. However, since this embodiment has many elements common to the fifth embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the fifth embodiment, the hysteresis characteristic is provided by making the friction coefficient of the portion of the sliding resistance generator 182 that contacts the piston 32 different between the stepping stroke and the return stroke. In the present embodiment, the piston 3 of the sliding resistance generator 200
The hysteresis characteristic is provided by making the area of the portion in contact with 2 different between the stepping stroke and the return stroke.

More specifically, as shown in FIG. 19, as in the fourth embodiment, the cross section of the sliding resistance generator 200 is in contact with the outer peripheral surface of the piston 32 with a convex surface.
02. Sliding resistance generator 200
This is to make the portion in contact with the piston 32 different between the stepping stroke and the return stroke. However, the cross section of the contact portion 202 is different from that in the fourth embodiment,
The shape is asymmetric. Specifically, the surface of the contact portion 202 has the right side in the figure, that is, the first slope 204 on the rear side in the direction in which the piston 32 moves when the operation force or the operation stroke increases, and the left side, that is, the operation force or the operation stroke. The first slope 204 is configured to be shorter than the length of the second slope 206 while being constituted by the second slope 206 on the rear side in the direction in which the piston 32 moves when decreasing. Is smaller than the area of the second slope 206.

In the stepping-in stroke, as shown in FIG. 20A, the sliding resistance generator 200 has a narrow first slope 204.
Therefore, the sliding resistance of the piston 32 is reduced, and the operation stroke is increased. On the other hand, in the return stroke, as shown in FIG.
Since the sliding resistance generator 200 comes into contact with the piston 32 on the wide second slope 206, the sliding resistance of the piston 32 increases, and the operation stroke decreases. As described above, in the present embodiment, the hysteresis characteristic is provided by making the area of the portion of the sliding resistance generator 200 that comes into contact with the piston 32 different between the step-in stroke and the return stroke. .

As is apparent from the above description, in this embodiment, the sliding resistance generator 200 constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to a seventh embodiment of the present invention will be described. However, since this embodiment has many elements common to the second embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the second embodiment, the selective damper 120 as a hysteresis characteristic imparting mechanism is provided on the brake pedal 10, but in this embodiment, it is provided on the rod 18. Specifically, as shown in FIG. 21, the rod 18 penetrates a fixing member 220 attached to the vehicle body, and a sliding resistance generator 222 is brought into close contact with the rod 18 and the fixing member 220. . The shape of the sliding resistance generator 222 and the shape of the groove 224 in which it is mounted can be the same as those in the third to sixth embodiments.

In this embodiment, since the sliding resistance of the rod 18 is made smaller in the stepping stroke than in the return stroke, the operation stroke corresponding to the same operating force is made shorter in the stepping than in the return stroke. In the present embodiment, the hysteresis characteristic is thus given to the brake operation characteristic.

As is apparent from the above description, in this embodiment, the sliding resistance generator 222 constitutes a "hysteresis characteristic imparting mechanism".

Next, an operation stroke generating device according to an eighth embodiment of the present invention will be described. However, since this embodiment has many elements common to the first embodiment, detailed description of common elements will be omitted by using the same reference numerals, and only different elements will be described in detail.

In the first embodiment, as shown in FIG. 2, a hysteresis elastic body 42 is disposed in the housing 24 between the bottom (the left end in the figure) and the piston 32 in the housing 24. . On the other hand, in the present embodiment, as shown in FIG. 22, a first elastic body 244 is disposed between a bottom of a housing 240 corresponding to the housing 24 and a piston 242 corresponding to the piston 32. I have. The first elastic body 244 can be made of a material mainly composed of rubber or a material mainly composed of urethane foam. The bottom of the housing 240 is closed by the plug 46 as in the first embodiment. Further, a flange 26, a stopper 58, and a communication hole 62 are formed in the housing 240, as in the first embodiment.

The outer peripheral surface of the first elastic body 244 has a tapered shape, and the sectional area of the first elastic body 244 is reduced as the distance from the piston 242 in the axial direction increases. Further, a through hole is formed in the center of the first elastic body 244, and the shaft portion 246 of the piston 242 is inserted through the through hole. The shaft portion 246 is capable of abutting against the bottom surface of the plug 46 at the distal end surface thereof, and the abutment defines the stroke end of the piston 242, that is, the stroke end of the brake pedal 10. Shaft 2
Gap L ₃ is formed between the 46 bottom of the distal end surface and the plug 46 of the.

A second elastic body 248 is attached to the plug 46. The second elastic body 248 is attached at a position facing the bottom surface of the concave portion 250 formed on the distal end surface of the shaft portion 246. Between the bottom surface of the second elastic member 248 and the recess 250, the gap L ₃ smaller gap L ₄ is formed. The second elastic body 248 can be made of a material mainly composed of rubber or a material mainly composed of urethane foam.

Next, the operation of the operation stroke generating device will be described. When it operating stroke S _P brake pedal 10 is depressed is increased, the piston 24
2 is advanced (moved to the left in the figure). When the piston 242 is advanced, the first elastic body 244 is compressed in the axial direction. When the first elastic body 244 is compressed in the axial direction, the first elastic body 244 is bent outward (expanded) in the radial direction, so that the outer peripheral surface of the first elastic body 244 and the cylinder 240 are compressed. The radial gap with the inner peripheral surface is reduced and eventually disappears. When the radial gap is eliminated, the first elastic body 244 is pressed against the inner peripheral surface of the cylinder 240 on the outer peripheral surface thereof. As a result, sliding resistance between the first elastic body 244 and the cylinder 240 occurs.

In this state, the brake pedal 10 is depressed.
Loosen its operating stroke S _PIs reduced
And the first elastic body 244 will be restored by its elasticity.
And

[0064] The sliding resistance between the first elastic body 244 and the cylinder 240, the operation stroke S _P corresponding to the same operating force F _P is greater than at the time of increase during reduction of the operation force F _P. Thus, in the present embodiment,
The first elastic member 244, a hysteresis characteristic is imparted to the brake operation feeling is the relationship between the operation stroke S _P and the operating force F _P.

The brake operation feeling depends on the behavior when the first elastic body 244 is elastically deformed. This is because the elastic deformation behavior is considered to affect the sliding resistance between the first elastic body 244 and the cylinder 240 and the amount by which the first elastic body 244 is elastically deformed (the amount of deflection in the axial direction). Therefore, in order to always realize the same brake operation feeling, the first elastic body 24 is required.
It is necessary to ensure that the elastic deformation behaviors of No. 4 are the same as possible in each braking operation, that is, to improve the possibility that the same elastic deformation behavior is reproduced.

On the other hand, a relationship is generally established between the cross-sectional area of the elastic body and the elastic coefficient such that the smaller the cross-sectional area, the lower the elastic coefficient. Further, the elastic body can be easily elastically deformed as the elastic coefficient is smaller.

In this embodiment, the cross-sectional area of the first elastic body 244 is minimized at a specific portion in the axial direction of the first elastic body 244, whereby the elastic coefficient of the first elastic body 244 is also minimized. As a result, the first elastic body 244 has a portion that is easily bent outward in the radial direction (a portion that is easily elastically deformed) at a specific position in the axial direction. Therefore, in the present embodiment, when the first elastic body 244 is compressed, it is promoted that the first elastic body 244 is always elastically deformed with the same behavior, such that the first elastic body 244 is flexed radially outward with the same portion as a node. . Therefore, according to the present embodiment, the brake operation feeling is realized as much as possible in each brake operation.

Furthermore, in the present embodiment, when the gap L ₄ disappears as a result of the brake pedal 10 being deeply depressed, thereafter, the first elastic body 244 and the second elastic body 248
Elastic force is caused to act on the piston 242 in parallel with, as a result, as shown by the solid line in FIG. 23, the increase gradient of the operating stroke S _P with respect to the increase in the operating force F _P becomes gentle. Then, the brake pedal 10 is depressed further deeply, as a result, the gap L ₃ disappears, increasing gradient of operating stroke S _P becomes zero. In the same figure, a broken line graph shows an experimental result of a comparative example in which the second elastic body 248 is removed from the present embodiment. As is apparent from the broken line graph, in the comparative example, among the brake pedal 10 does not reach its stroke end, an increase gradient of the operating stroke S _P is the set value is not 0, when it reaches the stroke end (Gap L ₃
Suddenly decreases to zero). In contrast, in the present embodiment, when the brake pedal 10 is approaching that of the stroke end, first, it decreases to a value increasing gradient of operating stroke S _P is not zero from the set value, then decreases to zero. The brake pedal 10 does not suddenly decrease to 0, and as a result, as the brake pedal 10 approaches the stroke end, the feeling of depression of the brake pedal 10 gradually becomes hard.

In this embodiment, the first elastic body 244
One end of a peripheral component (eg, a fixing member)
The cross-sectional area of those in contact with is smaller than elsewhere, thereby also minimizing the modulus of elasticity. The small elastic modulus of the first elastic member 244 at the contact portion with the surrounding components means that the elastic force of the first elastic member 244 hardly changes even if the shape of the contact portion is slightly varied. This means that variations in the shape of the contact portion can be easily absorbed. Therefore, according to the present embodiment, at least one of the two ends of the first elastic body 244, which is in contact with the peripheral component, has a smaller elastic modulus than the other portions, so that the shape variation of the contact portion is reduced. Nevertheless, the initial load of the operating force F _P is stabilized.

As is apparent from the above description, in the present embodiment, the first elastic body 244 constitutes a “first elastic body”, and the first elastic body 244 and the cylinder 240 cooperate with each other to form “first elastic body”. This constitutes a "hysteresis characteristic imparting mechanism". Also, the second elastic body 248 is a “second elastic body”
Configure is the initial length of the gap L ₄ corresponds to a "set distance".

It should be noted that, in this embodiment,
The fact that the cross-sectional area of the first elastic body 244 is reduced at a specific position in the axial direction and that the elastic deformation behavior of the first elastic body 244 is stabilized, the smaller the cross-sectional area is, the smaller the elastic coefficient becomes. Although they are described in association with each other by the fact that they tend to be elastically deformed, in some cases, they can be described in association with each other based on the fact that stress is easily concentrated on a portion having a small cross-sectional area and easily deformed elastically.

[0072] In more added that, in the present embodiment, in order to ensure that the deformation of the first elastic member 244 corresponding to the operating force F _P is always performed in the same manner, the cross-sectional shape of the first elastic member 244 Is varied in its axial direction, but the embodiment can take various forms. FIG.
Shows a first elastic body 260 having a cross-sectional shape different from that of the first elastic body 244 in a cross-sectional view. This first elastic body 26
At 0, the cross-sectional shape is changed in the axial direction at both ends in the axial direction so that the cross-sectional area becomes smaller and the elastic coefficient becomes smaller at the other portions.

[0073] In more added that, in the present embodiment, using the fact that the sliding resistance of the elastic body to be moved relative with the braking operation and the fixed member are different from each other in time decreases when increasing the operating force F _P by, although hysteresis brake operation feeling is the relationship between the operating force F _P and the operating stroke S _P is adapted to be applied, jointly with the hysteresis characteristic of such properties and the elastic member itself According to the present invention, the present invention is implemented such that the hysteresis characteristic is given to the brake operation feeling, or the present invention is implemented such that the hysteresis characteristic is given to the brake operation feeling only by the hysteresis characteristic of the elastic body itself. Is possible.

In addition, in this embodiment, the cross-sectional area and the elastic modulus of the first elastic body 244 are continuously changed in the axial direction thereof, but can be changed discontinuously. It is. According to this aspect,
A portion having a small elastic coefficient is locally present.

As described above, some embodiments of the present invention have been described in detail with reference to the drawings.
The present invention includes various modifications and improvements based on the knowledge of those skilled in the art, including the embodiments described in the section [Problems to be Solved by the Invention, Problem Solving Means and Effects of the Invention]. The present invention can be implemented.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a fluidless type brake device including a fluidless type brake operation stroke generating device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view showing the operation stroke generating device.

FIG. 3 is a graph showing elastic characteristics of the hysteresis elastic body in FIG.

FIG. 4 is a graph showing elastic characteristics of the spring in FIG.

FIG. 5 is a graph showing brake operation characteristics of the operation stroke generating device of FIG. 1;

FIG. 6 shows an electric brake control of the brake device of FIG. 1;
Operation stroke S realized _PBetween vehicle and vehicle deceleration G
It is a graph which shows a relationship.

FIG. 7 is a flowchart showing a brake control routine executed by a computer to perform the electric brake control.

FIG. 8 is a partial sectional front view showing a fluidless type brake operation stroke generating device according to a second embodiment of the present invention.

FIG. 9 is a front view showing a relationship between a selective damper and a brake pedal in FIG. 8;

FIG. 10 is a front sectional view showing a main part of the selective damper in FIG. 9;

FIG. 11 is a graph showing brake operation characteristics of the operation stroke generating device.

FIG. 12 is a front sectional view showing a sliding resistance generator in a fluidless type brake operation stroke generating device according to a third embodiment of the present invention.

FIG. 13 is a graph showing brake operation characteristics of the operation stroke generating device of FIG.

FIG. 14 is a front sectional view showing a main part of a fluidless type brake operation stroke generating device according to a fourth embodiment of the present invention.

FIG. 15 is a partial cross-sectional front view for explaining the principle of giving the hysteresis characteristic to the brake operation characteristic by the sliding resistance generator in FIG.

FIG. 16 is a front sectional view showing a main part of a fluidless type brake operation stroke generating device according to a fifth embodiment of the present invention.

FIG. 17 is a sectional view showing the sliding resistance generator in FIG.

18 is a partial cross-sectional front view for explaining the principle that the sliding resistance generator of FIG. 17 gives hysteresis characteristics to brake operation characteristics.

FIG. 19 is a sectional view showing a sliding resistance generator in a fluidless type brake operation stroke generator according to a sixth embodiment of the present invention.

20 is a partial cross-sectional front view for explaining the principle that the sliding resistance generator of FIG. 19 provides hysteresis characteristics to brake operation characteristics.

FIG. 21 is a partial cross-sectional front view showing a fluidless type brake operation stroke generating device according to a seventh embodiment of the present invention.

FIG. 22 is a partial sectional front view showing a fluidless type brake operation stroke generating device according to an eighth embodiment of the present invention.

FIG. 23 is a graph for explaining a function of a second elastic body in the operation stroke generating device of FIG. 22;

FIG. 24 is a front sectional view showing a first elastic body different from the first elastic body in FIG. 22;

[Explanation of symbols]

10: Brake pedal 20: Fluidless type brake operation stroke generator 42: Hysteresis elastic body 52: Spring 120: Selective damper 150, 160, 182, 200, 222: Sliding resistance generator 244, 260 First elastic body 248 Second elastic body

Claims (6)

[Claims] The present invention is used in a fluid-less type brake device that brakes a vehicle in response to a brake operation without using fluid, and generates an operation stroke corresponding to an operation force of the brake operation member in the brake operation member without using fluid. A fluidless type brake operation stroke generating device, wherein a fluid is provided with a hysteresis characteristic imparting mechanism for imparting a hysteresis characteristic without using fluid to a brake operation characteristic which is a relationship between the operation force and the operation stroke. Less type brake operation stroke generator. 2. The hysteresis characteristic imparting mechanism includes a hysteresis elastic body whose length is elastically changed in accordance with a received force and whose relationship between the force and the length is made of a material having a hysteresis characteristic. 2. The fluidless type brake operation stroke generating device according to claim 1, wherein the hysteresis elastic body imparts a hysteresis characteristic to the brake operation characteristic. 3. The elastic body according to claim 1, wherein the length is elastically changed in accordance with the received force, and the relationship between the force and the length is made of a material having substantially no hysteresis characteristics. The fluidless type brake operation stroke generating device according to claim 2, which is provided in series with the elastic body. 4. A fluidless type brake operation stroke generating apparatus according to claim 3, wherein said hysteresis elastic body is softer than said normal elastic body. 5. A first elastic body, wherein said hysteresis characteristic imparting mechanism is elastically deformed in response to a force received, and imparts a hysteresis characteristic to said brake operation characteristic based on said elastic deformation. The fluidless type brake operation stroke generating device according to any one of claims 1 to 4, including a device in which an easy part is set. 6. A stroke end of said brake operating member is defined by two members being approached and separated from each other in accordance with an increase and a decrease in said operating force, respectively. A force provided on at least one of the two members to prevent the two members from further approaching each other after the two members approach each other and the distance between the two members reaches a set distance. The fluidless type brake operation stroke generating device according to any one of claims 1 to 5, further comprising a second elastic body that acts on the brake.