JP2006240483A - Damper for accelerator cable, and accelerator cable with damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damper for an accelerator cable capable of considerably improving the elastic characteristic without degrading the vibration-isolating performance, and an accelerator cable with the damper for the accelerator cable. <P>SOLUTION: The substantially cylindrical damper for the accelerator cable is attached to an outer circumference of an end of an inner cable 3 for the accelerator cable, and interposed between an accelerator pedal 2 and a cable end member of the inner cable 3. A deflection-load curve consists of a first range in which the load is increased at the predetermined gradient in a substantially proportional manner from the origin, and a second range in which the load is changed at the gradient of zero or the positive gradient smaller than the predetermined gradient, where the axis of abscissa denotes the deflection caused by the compression in the axial direction and the axis of ordinate denotes the load to cause the deformation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an accelerator cable damper. More specifically, the present invention relates to an accelerator cable damper used for connecting a throttle valve operating accelerator cable inner cable to an automobile or the like, and a damper-equipped accelerator cable including the accelerator cable damper.

JP 2000-074037 JP 09-317502 A JP 05-209613 JP 08-042367 A JP 08-326567 A JP 2000-326756 A JP 2004-192316 A

  As a conventional example of an accelerator cable damper, there is a damper 100 shown in FIG. The damper 100 includes a pedal attachment portion 101 that is attached to the accelerator pedal via an attachment member, a cable engagement portion 102 for engaging the cable end member of the inner cable, and the pedal attachment portion 101 and the cable engagement. It is formed between the portion 102 and a barrel-shaped side wall 103 whose center portion is curved outward so that elastic deformation is easy. The pedal mounting portion 101 and the cable locking portion 102 are formed with a through hole 101a for passing an inner cable extending from the engine side.

  The damper 100 molded in this way attenuates vibration from the engine side that is transmitted to the accelerator pedal via the inner cable. When the accelerator pedal is depressed, the accelerator pedal compresses the damper 100 inward from the pedal mounting portion 101 side, the side wall 103 is deformed, and the pedal mounting portion 101 and the cable locking portion 102 are brought into close contact, and then the inner cable is pulled. The operating force is transmitted to the throttle valve side of the engine. As described above, the side wall 103 provides a constant inner cable operation amount and load with respect to the accelerator pedal operation amount. A graph of the amount of deflection and the load value of the damper 100 is shown by a broken line in FIG. The vertical axis of the graph of FIG. 3 is the compression load (load), and the horizontal axis is the amount of deflection at that time.

  In addition, as a prior art, an accelerator cable is fixed to a wall surface formed on a vehicle body as in Patent Document 1 or 2 via a member that suppresses vibration such as rubber, and an inner cable as in Patent Document 3 The outer casing that houses the vehicle is float-supported using a cushion rubber on the wall separating the outside of the vehicle interior, or the installation position of the accelerator cable on the vehicle body side as in Patent Documents 4 to 6, or As disclosed in Patent Document 7, there is a structure in which a hydraulic damper is provided in a movable accelerator pedal device to attenuate input vibration caused by road surface vibration.

  The vibration transmitted from the engine side by the inner cable is transmitted to the accelerator pedal via the damper and finally transmitted to the driver. In the conventional damper 100 shown in FIG. 8, the rubber hardness is high and the vibration isolating performance is insufficient. As shown in FIG. 5, generally, when the rubber hardness is increased, the dynamic magnification is also increased, and the vibration transmission rate is increased. On the other hand, when the rubber hardness is lowered, the dynamic magnification is also lowered, and the transmission rate of vibration is also reduced. The “dynamic magnification” means the ratio (kd / ks) between the dynamic spring constant (kd) and the static spring constant (ks), and is also called “dynamic magnification”. In addition, when looking at the characteristics of the amount of flexure of the damper (stroke of the accelerator pedal) and the load (accelerator pedal operation load) indicated by the broken line in FIG. 3, the region where the accelerator pedal is depressed to a certain extent (symbol P in FIG. 3). It can be seen that buckling occurs in which the load decreases despite an increase in deflection. If the buckling region P exists, the operation feeling of the accelerator pedal is greatly impaired. However, if the rubber hardness is increased in order to eliminate buckling, the vibration isolating performance is reduced. Conversely, if the rubber hardness is simply reduced in order to improve the anti-vibration performance, the above-described buckling characteristics will be deteriorated. Thus, the vibration isolation of the damper and the operation feeling are contradictory.

  In view of the above, the present invention provides an accelerator cable damper capable of greatly improving the elastic characteristics without deteriorating the vibration isolation performance, and an accelerator cable with a damper including the accelerator cable damper. The challenge is to do.

  The accelerator cable damper according to the present invention (Claim 1) is mounted on the outer periphery of the end portion of the inner cable of the accelerator cable and is interposed between the accelerator pedal and the cable end member of the inner cable. A first damper in which a deflection-load curve increases at a predetermined gradient substantially proportionally from the origin when a horizontal axis is a deflection caused by axial compression and a vertical axis is a load that causes the deformation. It is characterized by comprising a region and a second region that transitions with a zero or positive gradient smaller than the gradient.

  Such a damper has a thick disk-like cable locking portion that locks the cable end member of the inner cable at one end of the accelerator cable damper, and a thick disk that attaches the accelerator pedal to the other end. A pedal-shaped pedal mounting portion, and between the cable locking portion and the pedal mounting portion, there is a barrel-shaped side wall curved outward at the center, and the axial length is 23 to 27 mm. The outer diameter in the vicinity of the center is preferably 19 to 21 mm, and the thickness of the side wall is preferably 3 to 5 mm (Claim 2).

  In addition, it is preferable that a bead portion bulging outward is formed at a central portion of each of the cable locking portion and the pedal attachment portion. Furthermore, what consists of a rubber-type material whose rubber hardness is 50-60Hs is preferable (Claim 4). Moreover, what consists of a rubber-type material whose dynamic magnification is 1.3-2.1 is preferable. Furthermore, the accelerator cable with a damper according to the present invention includes the control cable including the outer casing, the inner cable slidably accommodated in the outer casing, and the above-described inner cable attached to the end of the inner cable of the control cable. It comprises an accelerator cable damper (claim 6).

  The load-deflection curve of the damper for an accelerator cable of the present invention (Claim 1) has a steep slope which is a ratio of the increase amount of the damper and the increase amount of the accelerator pedal to the increase amount of the deflection amount. It consists of a first region in a certain first half and a second region in the latter half that becomes gentle thereafter. The first region having a steep inclination is a part related to vibration isolation performance, and a load corresponding to at least the tension of the inner cable is applied, and the vibration isolation function is exhibited in this state.

  The second region is a region until the side wall starts to come into close contact from the vicinity of the center and finally the entire side wall comes into close contact. Although the flexure of the damper and the load that causes the flexure increase monotonously, since it shifts at least at a gradient of 0, there is no unpleasant feeling of the accelerator operation that reduces the load halfway while the accelerator pedal is depressed. .

  Such a damper has a thick disk-like cable locking part for locking the cable end member of the inner cable at one end of the accelerator cable damper, and the accelerator pedal is connected to the other end via an attachment member. It has thick disc-shaped pedal mounting parts to be attached, and has a barrel-shaped side wall curved outward near the center between the cable locking part and the pedal mounting part, and has an axial length. When the outer diameter in the vicinity of the center is 19 to 21 mm and the thickness of the side wall is 3 to 5 mm (Claim 2), it is more difficult to buckle when the axial load increases. . That is, since the cross-sectional area of the central part of the side wall is large, the compressive stress is low, and the cross-sectional secondary moment is large, so that the rigidity against the bending moment is high.

  In addition, when a bead portion bulging outward is formed at the center portion of each of the cable locking portion and the pedal mounting portion of the damper (Claim 3), when a load due to compression is applied to the damper The both end portions of the side wall are firmly held by the bead portion, so that it is in a state of fixed support, so that it becomes more difficult to buckle. Further, when the rubber hardness (conforming to JIS K 6253) is 50-60Hs as the material of the damper (Claim 4), even if the rigidity is increased depending on the shape, the gradient of the load-deflection curve can be lowered. Performance does not decrease. Moreover, since it becomes easy to compress-deform, a dynamic magnification can be reduced, the vibration transmitted from an engine side to an accelerator pedal via an inner cable can be reduced, and the comfortable operation feeling of an accelerator pedal can be obtained. Further, when a rubber material having a dynamic magnification of 1.3 to 2.1 is used as a material of the damper (Claim 5), vibration transmitted from the engine side to the accelerator pedal via the inner cable is further reduced. be able to. Furthermore, in the accelerator cable with a damper according to the present invention (Claim 6), the above-described accelerator cable damper is attached to the end portion of the inner cable of the control cable. Therefore, since it can be handled as one subassembly, transportation, storage or assembly can be facilitated.

  Next, an embodiment of a damper according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic side sectional view of an accelerator cable damper according to the present invention, FIG. 2 is a schematic view showing a state where the damper of FIG. 1 is attached, and FIG. 3 is a deflection-load curve when the damper of FIGS. 4 is a partial longitudinal sectional view used for comparing the shapes of the dampers of FIGS. 1 and 8, and FIG. 5a is a deflection-load curve between the damper of the present invention and the damper of the comparative example before the durability test. FIG. 5b is a graph showing a deflection-load curve between the damper of the present invention and the comparative example after the durability test, and FIG. 6 is a dynamic magnification of the ethylene-propylene-diene terpolymer (EPDM) material and rubber. FIG. 7 is a graph showing the frequency of the accelerator pedal when the damper shown in FIGS. 1 and 8 is used in an actual vehicle.

  First, an accelerator pedal mounting structure in which the accelerator cable damper of the present invention is used will be described with reference to FIG. The accelerator pedal attachment structure shown in FIG. 2 includes a damper 1, an accelerator pedal 2 to which an end of the damper 1 on the engine room side is attached, and passes through the accelerator pedal 2 to pass through the inside of the damper 1. 2 and an inner cable 3 that is locked at the end beyond the opposite end.

  The damper 1 is formed in a substantially cylindrical shape so that the inner cable 3 can be accommodated therein, a disc-shaped pedal mounting portion 1a to which an operation portion of an accelerator pedal described later is mounted, and an inner cable 3 Is formed of a disk-shaped cable locking portion 1b and a central portion 1c formed continuously between the pedal mounting portion 1a and the cable locking portion 1b. The central part 1c is substantially cylindrical so that it can bend flexibly when the pedal mounting part 1a and the cable locking part 1b are compressed, and the cylindrical side wall is curved outward. (Substantially barrel shape). The axial length of the damper 1 formed in this manner is 23 to 27 mm, preferably 24 to 26 mm. In order to maintain compatibility, the actual dimensions are the same as those of the conventional product (see FIG. 4).

A pedal side through hole 1d is formed in the pedal mounting portion 1a, and an inner cable 3 extending from the engine side is passed through the pedal mounting portion 1a. A cable side through hole 1e is formed in the cable locking portion 1b. The end portion of the inner cable 3 extends outward from the inside of the damper 1 through the cable side through hole 1e, and is engaged with the outer surface of the cable locking portion 1b by the enormous portion formed at the end portion of the inner cable 3 described later. Stopped. The pedal attachment portion 1a and the cable locking portion 1b are disk-like members having substantially the same diameter. The disk-shaped member has a thickness of 5 to 9 mm and an outer diameter of 12 to 16 mm. And the corner | angular part of the end surface outer periphery of those disk-shaped members is chamfered 2-4 mm. The chamfering prevents the concentration of stress from occurring on the outer periphery of the end surface and smoothes the entire elastic deformation.
Further, the portions left by the chamfering of the outer pedal mounting portion 1a and the cable locking portion 1b where the central portion 1c is formed are bead portions 1f and 1f. The base portion of the central portion 1c continuous with the bead portion 1f is smoothly formed in an arc shape of 0.5 to 2 mm toward the inside.

  The central portion 1c is continuously disposed between the pedal attachment portion 1a and the cable locking portion 1b, and includes a side wall that is curved outward. The outer diameter of the outer curved portion is 18 to 22 mm, preferably 19 to 21 mm. As a result, the ratio between the maximum diameter and the longitudinal dimension is 1.21-1.24, which is smaller than the conventional product. Moreover, the thickness of the side wall of the center part 1c is 3-6 mm, Preferably it is 3.5-5 mm. Moreover, the curvature radius of the outer surface of the said curved side wall in a longitudinal section is 11-14, Preferably it is 11.5-13.5 mm, The curvature radius of an inner surface is 7-10 mm, Preferably it is 7.5-9. 5 mm. As can be seen from FIG. 4, these radii of curvature are small compared to the conventional product.

  The material of the damper 1 can be natural rubber or EPDM. The rubber has a hardness of 50 to 60 (Hs), preferably 53 to 57 (Hs). This hardness range is considerably softer than the conventional product of 60 to 70 (Hs).

  The accelerator pedal 2 has a bent shape that protrudes toward the front of the vehicle body. The protruding portion in the shape of a square is a fulcrum 2a pivotally supported by a support portion 4 provided inside the vehicle body. The portion extending from the fulcrum 2a to the rear of the vehicle body and being stepped on by the leg 5 is the pedal 2b, and the portion extending upward at the end opposite to the pedal 2b pushes the pedal mounting portion 1a of the damper 1. The operation unit 2c. The accelerator pedal 2 has a vertical movement (arrows U and D in the figure) that depresses and releases the pedal 2b with the legs 5 via a fulcrum 2a of an operation portion 2c formed on the end opposite to the pedal 2b. It is converted into a substantially left-right direction (arrows L and R in the figure) and transmitted to the inner cable 3 via the damper 1. The operation portion 2c is assembled with a cylindrical portion 2d made of polyamide resin that fits into the pedal-side through hole 1d of the damper 1, and the inner cable 3 passes through the cylindrical portion 2d and passes through the inside of the damper 1. Be guided to.

  The accelerator cable has one end locked to the engine side, is guided by an outer casing from the engine side to the wall surface of the vehicle body, is supported by the wall surface portion of the vehicle body, and is stored in the inner cable 3. Only extends inside the car. A portion of the inner cable 3 that extends inside the vehicle extends to the outside from the cable side through hole 1 e of the damper 1. An enormous portion 3 a is formed by zinc die casting or the like from the hole diameter of the cable side through hole 1 e at a portion extending to the outside of the inner cable 3 and is locked to the cable locking portion 1 b of the damper 1.

  The support portion 4 is pivotally supported by a fulcrum 2a and is provided with a return spring 4a. The return spring 4a pushes back the depressed pedal 2b in the U direction which is the original position. And the operation part 2c also returns to the R direction which is the original position. At that time, the returned accelerator pedal 2 is returned until the contact surface 2e on the back side of the operation portion 2c hits a stopper 4b extending upward from the support portion 4.

  Next, the elastic characteristic of the damper 1 in this embodiment is demonstrated using FIG. The vertical axis shown in FIG. 3 shows the load applied to the damper 1 of FIG. 2, and the horizontal axis shows the deflection of the damper 1. The broken line represents the damper 100 (see FIG. 8) shown as a conventional example. As shown in FIG. 3, in the damper 1, there is no buckling region in which the load drops in the middle of the stroke as indicated by the symbol P, and therefore, the accelerator operation can be performed smoothly and as expected.

  Next, the damper 1 and the conventional damper 100 (two-dot chain line in the figure) will be compared using FIG. The damper 1 shown in FIG. 4 has a bead portion 1f extending outward. Since the bead portion 1f is formed in the vicinity corresponding to both end portions of the center portion 1c, both ends of the center portion 1c are firmly held to support the bending and prevent buckling of the center portion 1c. Yes.

  Table 1 shows the static spring characteristics and the dynamic spring characteristics of the dampers of Examples 1 to 3 having the form of the damper of FIG. 1 and changing the material or hardness and the damper 100 of FIG. 8 used as a comparative example. . The dimensions (see FIG. 1) of the dampers of Examples 1 to 3 are about 25 mm in the total length in the axial direction, about 4.5 mm in thickness of the pedal attachment portion 1a and the cable locking portion 1b, and about 20 mm in outer diameter. And the corner | angular part of the end surface outer periphery of those disk-shaped members is chamfered about 3 mm. The thickness of the side wall of the central portion 1c is about 4.2 mm, the curvature radius of the outer surface of the curved side wall in the longitudinal section is about 12.5 mm, and the curvature radius of the inner surface is about 8.3 mm. The material of the damper thus formed is natural rubber, and rubber hardness is 50 (Hs) as Example 1, and the material is natural rubber and rubber hardness is 55 (Hs) as Example 2. A material having EPDM and a rubber hardness of 50 (Hs) is referred to as Example 3. The dimensions of the damper used as a comparative example (see FIG. 8) are about 25 mm in the total length in the axial direction, about 6.5 mm in thickness of the pedal mounting portion 101 and the cable locking portion 102, and about 15 mm in outer diameter. . And the corner | angular part of the end surface outer periphery of those disk-shaped members is chamfered about 1 mm. Moreover, the wall thickness of the barrel-shaped side wall 103 is about 2.7 mm, the curvature radius of the outer surface of the curved side wall in the longitudinal section is about 15 mm, and the curvature radius of the inner surface is about 12.3 mm. The material is natural rubber and the rubber hardness is 65 (Hs).

  In addition, the static spring characteristic here indicates a load value (N) when a predetermined displacement is applied to the damper. On the other hand, the dynamic spring characteristic indicates a load value / vibration displacement (N / mm) when a predetermined vibration displacement is applied in a state where a predetermined initial displacement is applied to the damper. In addition, the test method of a static spring characteristic and a dynamic spring characteristic is based on JISK6394. As shown in Table 1, the dampers of Examples 1, 2, and 3 exhibit static spring characteristics substantially the same as the dampers of the comparative examples. However, the dynamic spring characteristics are greatly reduced as compared with the conventional example. Since the dynamic spring characteristics can be greatly reduced in this way, vibration isolation performance is high and vibration from the engine side is hardly transmitted to the driver via the inner cable 3. Therefore, the operation feeling of the accelerator pedal 2 can be improved.

  Next, the characteristics of the deflection and the load before and after the endurance test in which the 10 mm deflection is applied to the damper described above 100,000 times will be described. FIG. 5a shows the deflection-load curve of the damper before the durability test. FIG. 5b shows the deflection-load curve after the durability test. When the deflection-load curve after the endurance test shown in FIG. 5b is seen, in the damper of the comparative example, the buckled portion indicated by the symbol P disappears after the endurance test, but as a whole is a substantially S-shaped curve. In a curve that draws such a substantially S-shaped curve, the first half of the steep region is convex upward, and the anti-vibration effect is low. Further, the buckling region disappears in the subsequent region, but when the accelerator pedal is stepped on, it is easily bent from the middle, and the operation feeling of the accelerator pedal 2 is impaired. On the other hand, such a tendency was not recognized in Examples 1 and 2 formed so as not to cause buckling from the beginning.

  As described above, according to the dampers of the first and second embodiments, as shown by the solid line portion in FIG. 3, the first half proportional portion (first region) with a steep slope and the second half portion with a gentle slope thereafter. (Second region), and the latter half does not have a buckling portion like the symbol P. Therefore, the anti-vibration characteristic is excellent in the initial stage and there is no buckling region in the second half, so that a comfortable operating feeling can be provided for the driver who operates the accelerator pedal 2. Furthermore, since the dynamic spring characteristics can be reduced while having such characteristics, vibrations transmitted from the engine side to the accelerator pedal 2 and the legs 5 via the inner cable 3 can also be prevented.

  FIG. 7 shows the result of measuring the vibration of the accelerator pedal 2 when the damper of Example 1 (see FIG. 1) and the damper of the comparative example (see FIG. 8) are attached to an actual vehicle. The vibration transmitted from the engine is measured as the vibration of the accelerator pedal by a vibration sensor assembled to the accelerator pedal 2 via the inner cable 3. The horizontal axis of the graph indicates the engine speed. The vertical axis of the graph indicates the vibration level of the accelerator pedal with respect to the engine speed, which is 10 dB per scale. As shown in FIG. 7, according to the damper of the first embodiment, it can be seen that vibration from the engine is difficult to be transmitted to the accelerator pedal 2 when the engine speed is in the range of 2000 to 4000 rpm (within the dotted line in the figure). In this way, by using the damper of the present invention, it is possible to provide an accelerator cable damper that can improve the vibration-proof performance and further greatly improve the elastic characteristics.

FIG. 1 is a schematic sectional side view of a damper according to the present invention. FIG. 2 is a schematic view showing a state where the damper of FIG. 1 is attached. FIG. 3 is a graph showing a deflection-load curve when the damper of FIGS. 1 and 8 is used. FIG. 4 is a partial longitudinal sectional view used for comparing the shapes of the dampers shown in FIGS. 1 and 8. FIG. 5A is a graph showing a deflection-load curve between the damper of the present invention and the comparative example before the durability test, and FIG. 5B is a graph showing a deflection-load curve of the damper of the present invention and the comparative example after the durability test. FIG. 6 is a graph showing the relationship between the dynamic magnification of the EPDM material and the rubber hardness. FIG. 7 is a graph showing the frequency of the accelerator pedal when the damper of FIGS. 1 and 8 is used in an actual vehicle. FIG. 8 is a side sectional view showing a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Damper 1a Pedal attachment part 1b Cable latching part 1c Center part 1d Pedal side through hole 1e Cable side through hole 1f Bead part 2 Accelerator pedal 2a Pedestal 2b Pedal 2c Operation part 2d Cylindrical part 2e Contact surface 3 Inner cable 3a Enormous part 4 Support part 4a Return spring 4b Stopper 5 Leg

Claims (6)

An accelerator cable damper that is attached to the outer periphery of the end of the inner cable of the accelerator cable and is interposed between the accelerator pedal and the cable end member of the inner cable,
When the horizontal axis represents the deflection due to axial compression and the vertical axis represents the load that causes the deformation,
A damper for an accelerator cable comprising a first region in which a deflection-load curve increases at a predetermined gradient almost proportionally from the origin, and a second region in which the curve changes from 0 to a positive gradient smaller than the gradient. . A thick disk-like cable locking portion that locks the cable end member of the inner cable at one end of the damper,
A thick disc-shaped pedal mounting portion for attaching the accelerator pedal to the other end,
Between the cable locking part and the pedal mounting part, it has a barrel-shaped side wall that is curved outward near the center,
2. The accelerator cable damper according to claim 1, wherein an axial length is 23 to 27 mm, an outer diameter near the center is 19 to 21 mm, and a wall thickness is 3 to 5 mm.   The accelerator cable damper according to claim 2, wherein a bead portion bulging outward is formed at a central portion of each of the cable locking portion and the pedal attachment portion.   The accelerator cable damper according to claim 1, 2 or 3, comprising a rubber material having a rubber hardness of 50 to 60Hs.   The accelerator cable damper according to claim 1, 2, 3, or 4, comprising a rubber-based material having a dynamic magnification of 1.3 to 2.1. A control cable comprising an outer casing and an inner cable slidably housed in the outer casing;
The accelerator cable with a damper which consists of the damper for accelerator cables of Claims 1-5 attached to the edge part of the inner cable of the control cable.

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