JP4347784B2 - Anti-vibration rubber force measuring device using strain gauge and automobile suspension mechanism using it - Google Patents

Description

  The present invention relates to an anti-vibration rubber acting force measuring device capable of measuring the amount of distortion of a member due to an external force exerted on an automobile wheel, and an automobile suspension mechanism using the same.

  Conventionally, in order to improve the running stability of an automobile, it has been studied to suppress unstable vehicle behavior such as slip by giving a mechanical assistance to a driver's operation. Specifically, an anti-lock braking system (ABS) that suppresses wheel locking during braking is put into practical use, traction control that suppresses wheel slipping during sudden acceleration, and vehicle behavior stabilization are comprehensive. Vehicle control systems, such as vehicle stability control, which are controlled in the future are being studied.

  By the way, such vehicle control of an automobile is performed using various detection signals corresponding to the running state of the automobile. As one mechanism for detecting such a signal, an external force (road surface) acting on a wheel is used. Several acting force measuring devices for detecting a frictional force, a normal force), a road surface friction coefficient, and the like have been proposed. For example, those described in Patent Documents 1 and 2.

Japanese Patent No. 2628444 Japanese Patent Publication No. 8-20323

  However, as described in Patent Document 1, in the acting force measuring device having a structure in which a strain gauge is embedded by providing a hole in the axle, it is difficult to put into practical use in consideration of the strength, structure, manufacturability, etc. of the axle. Since it is necessary to provide a plurality of holes on the axle for detection in a plurality of directions, there is a problem that it is more difficult to put into practical use.

  Further, as described in Patent Document 2, in a working force measuring apparatus having a structure in which a strain gauge is attached to a component member of a suspension mechanism to detect shear strain, the strain gauge has a large member size. An operation of attaching to the suspension mechanism of the vehicle is required, and in some cases, it is necessary to process the constituent members of the suspension mechanism.

  Therefore, in view of the problems of the conventional mechanism, the present applicant has previously filed Japanese Patent Application No. 2003-063584 and provided detection means for detecting a load acting between the vehicle body and the wheels. A vibration isolator for suspension was proposed. Such a vibration isolator for a suspension can be realized, for example, by detecting the relative displacement amount of the inner shaft member and the outer cylinder member in the suspension bush by a displacement amount detection sensor. This does not adversely affect axle strength, wheel rigidity, tire performance, etc., and by installing a sensor for detection on the suspension bushing, sensor mounting work on the vehicle side and processing for mounting can be performed. This makes it possible to measure stress without applying it.

  However, as a result of further experiments and examinations by the present applicant, it has been found that there is still room for improvement in the mechanism employing the invention of the prior application.

  That is, the above-mentioned invention of the prior application shows a stress measuring means for detecting the relative displacement amount between the inner shaft member and the outer cylinder member of the suspension bush. However, since the inner shaft member and the outer cylinder member are elastically connected by the main rubber elastic body, which is an elastic body, the inner shaft member even if the same load is applied due to a change in rigidity of the main rubber elastic body. And the relative displacement amount of the outer cylinder member changes, and an error occurs in the external force acting on the wheel estimated from the detection result. In addition, since the rigidity of the main rubber elastic body changes relatively easily due to the temperature dependency of the main rubber elastic body and changes with time, there is a problem that an estimation error of the external force acting on the wheel is likely to occur.

  Here, the present invention has been made in the background as described above, and the problem to be solved is that the external force acting on the wheels of the automobile is changed to the rigidity change of the elastic body due to various factors. An object of the present invention is to realize an acting force measuring device having a novel structure that can easily realize a mechanism that can be detected without being affected.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

That is, the first aspect of the present invention relating to the acting force measuring device is that the inner shaft member and the outer cylinder member arranged in an extrapolated state spaced apart on the outer peripheral side of the inner shaft member are both of these members. In a cylindrical rubber mount elastically connected by a main rubber elastic body disposed between opposing surfaces in a direction perpendicular to the axis, an acting force measuring device for measuring an external force acting between the inner shaft member and the outer cylinder member. In addition, at least one of the inner shaft member and the outer cylinder member has a double structure that is overlapped in the radial direction, and a gap is partially provided between the overlapping surfaces in the radial direction in the double structure, The present invention is characterized in that a strain detecting means for detecting a strain amount is mounted on the overlapping surface facing the gap .

  In the acting force measuring apparatus configured according to this embodiment, by attaching strain detecting means for detecting the strain amount to at least one of the inner shaft member and the outer cylindrical member of the cylindrical rubber mount, Strain amount detection results by the strain detection means are not affected by external factors such as temperature dependence of the rubber elastic body and changes in stiffness due to changes over time, enabling stable strain amount detection. The external force acting on the wheel based on the detection result can be reliably and accurately estimated.

  In addition, strain detection means for detecting the strain amount is attached to at least one of the inner shaft member and outer cylinder member of the cylindrical rubber mount, so that the suspension parts and body of a vehicle having a relatively large size can be strained. It is not necessary to secure a space for disposing the detecting means or to perform a special disposing operation, and the acting force measuring device can be easily attached to the vehicle.

  In addition, a second aspect of the present invention relating to the acting force measuring apparatus is that, in the acting force measuring apparatus according to the first aspect, the gap is smaller than a region having a central angle of 45 degrees in the circumferential direction. It is characterized by being.
  In the acting force measuring apparatus having the structure according to this aspect, the gap is formed so as not to be continuous over the entire circumference in the circumferential direction. Therefore, it is possible to obtain a relatively large amount of strain at the mounting portion of the strain detecting means, enabling highly accurate detection, and at the same time ensuring sufficient rigidity of the member, and the cylindrical rubber mount It is possible to reduce or avoid the adverse effect on the anti-vibration performance.

  Further, a third aspect of the present invention relating to the acting force measuring device is that, in the acting force measuring device according to the first or second aspect, the gap is in the vicinity of the center in the axial direction of the inner shaft member and the outer cylinder member. It is formed.
  In the acting force measuring apparatus having the structure according to this aspect, a strain is generated due to the force in the twisting direction acting because the gap is formed near the axial center of the inner shaft member and the outer cylindrical member. The adverse effect on the detection result of the detection means is advantageously avoided, and the acting force in the direction perpendicular to the axis can be reliably detected.

The fourth aspect of the present invention relates acting force measuring device, before Symbol acting force measuring device according to the first to third one aspect, while the inner shaft member and the cylindrical, the inner shaft By providing a fixing rod that is inserted and fixed in the member, the inner shaft member is formed into a double structure in which the inner shaft member is overlapped in the radial direction .

In the acting force measuring apparatus having the structure according to this aspect, a gap is provided between the inner peripheral surface of the inner shaft member and the outer peripheral surface of the fixed rod at the site where the strain detecting means is mounted. Since the mounting portion of the shaft member on which the strain detecting means is mounted is not restrained by the fixed rod, it is easier to cause strain due to the acting force than other portions. Therefore, the acting force acting on the inner shaft member can be detected with high accuracy by the strain detecting means .

Further, a fifth aspect of the present invention relates acting force measuring device, the acting force measuring device according to the first to fourth one aspect, provided Bush mounting portion having a fitting hole, the The bush mounting portion is externally fitted and fixed to the outer cylinder member, thereby forming a double structure in which the outer cylinder member is overlapped in the radial direction .

In the acting force measuring device structured according to this embodiment, by providing a gap between the outer peripheral surface of the outer cylinder member and the inner peripheral surface of the bush mounting portion in the mounting portion of the strain detecting means , Since the mounting portion of the strain detecting means in the outer cylinder member is not restrained by the inner peripheral surface of the bush mounting portion, the strain due to the acting force is easily generated as compared with other portions. Therefore, the acting force acting on the outer cylinder member can be detected with high accuracy by the strain detecting means .

Further, a sixth aspect of the present invention relates acting force measuring device, the acting force measuring device according to the first to third one embodiment, at least one of the previous SL inner shaft member and the outer tubular member, A double cylinder structure in which the inner sleeve and the outer sleeve are fitted and fixed to each other is used to form a double structure in which the inner sleeve and the outer sleeve are overlapped in the radial direction .

In the acting force measuring apparatus having the structure according to this aspect, the strain detecting means is attached to any one of the overlapping surfaces of the inner and outer sleeves so that the strain detecting means is the inner peripheral surface of the inner shaft member. And / or exposure to the outer peripheral surface of an outer cylinder member can be prevented. Therefore, it is possible to prevent the strain detection means from being damaged while being attached to a vehicle, etc., and to prevent the strain detection means from being damaged during storage in a warehouse or transportation by a vehicle or a ship. Easy handling of force measuring device. In addition, the wiring for outputting the detection result detected by the strain detecting means to the outside can be easily performed, and the mounting work to the vehicle can be efficiently performed. Furthermore, by improving the sealing performance from the outside of the strain detection means , performance can be stabilized and durability can be improved.

In addition, the present invention employs the above-described cylindrical rubber mount as a suspension bush that is interposed in a connection portion of a vehicle suspension member (including an arm, a link, a rod, and the like) to a vehicle body. External force acting on the wheels of an automobile from the road surface by using the detection value obtained by the strain detection means, constituting the acting force measuring device according to any one of the first to sixth aspects of the present invention relating to An automobile suspension mechanism that seeks to satisfy the above requirements is also a feature.

  In the automobile suspension mechanism constructed according to this embodiment, the external force acting on the wheels of the automobile from the road surface can be detected easily and accurately without being affected by the change in rigidity of the main rubber elastic body. Is possible.

  As is apparent from the above description, in the acting force measuring device structured according to the present invention, the external force exerted on the wheel is converted into a change in rigidity based on a temperature change or a secular change of the elastic body constituting the rubber mount. It can be estimated quickly and reliably without being affected.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIGS. 1 to 3 show a suspension bush 10 as a cylindrical rubber mount provided with an acting force measuring device as a first embodiment of the present invention. The suspension bush 10 has a structure in which an inner cylinder fitting 12 as an inner shaft member and an outer cylinder fitting 14 as an outer cylinder member are elastically connected by a main rubber elastic body 16.

  More specifically, the inner cylinder fitting 12 is made of a rigid material having a small-diameter substantially cylindrical shape, while the outer cylinder fitting 14 is made of a large-diameter thin-cylindrical rigid material as a whole. Moreover, the upper part of the outer cylinder metal fitting 14 is bent toward radial direction outward, and the flange part 18 extended over the perimeter is formed. The inner cylinder fitting 12 and the outer cylinder fitting 14 are disposed on substantially the same central axis and are spaced apart from each other in the radial direction.

  A main rubber elastic body 16 having a substantially cylindrical shape as a whole is interposed between the opposing surfaces of the outer peripheral surface of the inner cylindrical metal member 12 and the inner peripheral surface of the outer cylindrical metal member 14, and The tube fittings 14 are each vulcanized and bonded. Further, a stopper rubber 20 protruding upward is integrally formed with the main rubber elastic body 16 on the upper portion of the main rubber elastic body 16 and is vulcanized and bonded to the upper surface of the flange portion 18 formed on the outer cylinder fitting 14. ing. Thus, the suspension bush 10 of the present embodiment is configured as an integrally vulcanized molded product in which the inner cylinder fitting 12 and the outer cylinder fitting 14 are vulcanized and bonded to the inner and outer peripheral surfaces of the main rubber elastic body 16. .

  Thus, as shown in FIG. 3, on the outer peripheral surface of the suspension bushing 10, that is, on the outer peripheral surface of the outer tube metal fitting 14, sensor mounting recesses 22a, 22b, 22c and 22d are formed. The sensor mounting recesses 22a to 22d are substantially octagonal when viewed from the front, and are formed by denting the outer peripheral surface of the outer cylindrical metal member 14 radially inward. In the present embodiment, such sensor mounting recesses are formed at four locations on the outer peripheral surface of the outer tube fitting 14, and sensor mounting recesses 22 a and 22 b formed at two locations of these are provided on the outer tube fitting 14. The sensor mounting recesses 22c and 22d formed so as to face each other in one radial direction and substantially perpendicular to the opposing direction of the sensor mounting recess 22a and the sensor mounting recess 22b. It forms so that it may mutually oppose in the radial direction of the outer cylinder metal fitting 14 to perform. In other words, each of the sensor mounting recesses 22a to 22d is formed on the outer peripheral surface of the outer cylinder fitting 14 so as to be positioned at equal separation distances in the circumferential direction.

  Strain gauges 24a, 24b, 24c, and 24d as strain detecting means are respectively attached to the substantially central portions of the sensor mounting recesses 22a to 22d. The strain gauges 24a to 24d are strain gauges that generate an electromotive force in accordance with the amount of strain of the outer cylindrical fitting 14 due to the action of an external force, and known resistance wire strain gauges, semiconductor strain gauges, and the like can be suitably employed. In the present embodiment, the strain gauge 24a and the strain gauge 24b are positioned opposite to each other in one radial direction of the outer tube fitting 14, and the strain gauge 24c and the strain gauge 24d are replaced by the strain gauge 24a and the strain gauge. 24b are opposed to each other in a radial direction substantially orthogonal to the facing direction of 24b.

  Lead wires 26a, 26b, 26c, and 26d for transmitting the electromotive force generated according to the strain amount to the outside are attached to the strain gauges 24a to 24d. One end of each of the lead wires 26a to 26d is connected to the lower end of each of the strain gauges 24a to 24d, and each of the lead wires 26a to 26d is connected to the lower end of each of the sensor mounting recesses 22a to 22d and extends downward. The other end is connected to an external arithmetic unit 30 that extends in the axial direction downward in 28d and is provided outside. The electromotive force generated according to the strain amount detected in the strain gauges 24a to 24d is transmitted to the external arithmetic device 30 by the lead wires 26a to 26d, and the external arithmetic device 30 is based on the detection result of the strain amount. The external force that acts on the wheels that do not perform is calculated.

  The suspension bush 10 including the acting force measuring device configured as described above is attached to a suspension component 32 as a suspension member including a suspension link, a suspension rod, and the like. More specifically, as shown in FIGS. 1 and 2, with respect to the fitting hole 37 formed in the bush attachment portion 36 formed at the end of the suspension arm 34 constituting the suspension component 32. The suspension bush 10 is fitted in an inserted state. The bush mounting portion 36 is formed of a substantially cylindrical rigid material, and has an inner diameter that is slightly smaller than the outer diameter of the suspension bush 10. The suspension bush 10 is press-fitted into the bush mounting portion 36. Thus, the suspension bush 10 is fixedly attached to the suspension component 32. Note that the strain gauges 24a to 24d disposed in the sensor mounting recesses 22a to 22d on the outer peripheral surface of the outer cylindrical metal fitting 14 are positioned away from the inner peripheral surface of the bush mounting portion 36 under such mounting conditions. I'm damned. Further, particularly in the present embodiment, the four strain gauges arranged in the two radial directions substantially orthogonal to the outer cylinder fitting 14 in the attached state of the suspension bush 10 to the suspension part 32 are the strain gauges 24a, 24b is positioned in the longitudinal direction of the vehicle, and strain gauges 24c and 24d are positioned in the lateral direction of the vehicle.

  Further, a fixing rod (not shown) that protrudes from a vehicle body (not shown) is inserted into the inner cylinder fitting 12 and the inner cylinder fitting 12 is fixed to the vehicle body by bolts, welding, or the like. Note that the relative displacement of the suspension bushing 10 with respect to the vehicle body is limited by bringing the upper surface of the stopper rubber 20 into contact with the vehicle body.

  In this way, the inner cylinder fitting 12 is fixed to the vehicle body (not shown), and the outer cylinder fitting 14 is fixed to the suspension component 32. The vehicle body and the suspension component 32 (not shown) are interposed via the suspension bush 10. It is elastically connected.

  In the present embodiment, the amount of strain in the vehicle front-rear direction and the vehicle left-right direction is determined based on the acting force exerted on the suspension bushing 10 from the wheel via the suspension part 32 by the strain gauges 24a, 24b, 24c, It will be detected by 24d. In the following (1) to (6), an example of means for accurately estimating the external force acting on the wheel based on the strain amount of the outer cylinder fitting 14 in this embodiment will be described.

(1) When an external force acting on the wheel is transmitted to the suspension bush 10 attached to the suspension component 32 during traveling of the automobile, the outer cylinder fitting 14 is displaced relative to the inner cylinder fitting 12. In the following description, the outer cylinder fitting 14 is relative to the inner cylinder fitting 12 in the vehicle front-rear direction (upward direction in FIG. 1, x direction in the following description), and in the vehicle left-right direction the vehicle right direction. (The right direction in FIG. 1, the y direction in the following description) and the vehicle up-down direction are assumed to be displaced in the vehicle upward direction (the upward direction in FIG. 2, the z direction in the following description).
(2) Due to the relative displacement, the outer cylindrical metal member 14 is distorted by the elastic force based on the elastic deformation of the main rubber elastic body 16, and each of the strain gauges 24a to 24d is caused according to the amount of strain. Detect power.
(3) Here, for example, when a tensile strain in the vehicle front-rear direction occurs at the location where the strain gauge 24a is disposed, a compressive strain of substantially the same magnitude occurs at the location where the strain gauge 24b is disposed in the vehicle longitudinal direction. Become. In addition, when a tensile strain in the vehicle left-right direction is generated at the site where the strain gauge 24c is disposed, a compressive strain of substantially the same magnitude is generated in the strain gauge 24d in the vehicle left-right direction. In other words, the strain gauges 24a and 24b generate electromotive forces that are substantially equal in magnitude and opposite in direction (sign) according to the strain in the vehicle front-rear direction, and respond to the strain in the vehicle left-right direction and vehicle vertical direction. Thus, the same electromotive force is generated when the directions are substantially equal in direction (sign). On the other hand, in the strain gauges 24c and 24d, in accordance with the strain in the vehicle left-right direction, the magnitudes are substantially equal and the direction (symbol) is generated in opposite directions, and in response to the strain in the vehicle longitudinal direction and the vehicle vertical direction, The same electromotive force is produced when the directions are substantially equal in magnitude (sign). In particular, in the present embodiment, the strain gauges 24a and 24b generate electromotive forces of the magnitudes E1, E2, and E3 according to the strain in the x, y, and z directions of the outer tube fitting 14, and It is assumed that the strain gauges 24c and 24d generate an electromotive force having a magnitude of E4, E5, and E6.
Therefore, in this embodiment, according to the detected strain amount,
Strain gauge 24a is (E1 + E2 + E3)
The strain gauge 24b is (-E1 + E2 + E3)
The strain gauge 24c is {E4 + (− E5) + E6}
Strain gauge 24d is (E4 + E5 + E6)
Each of the electromotive forces is generated.
(4) The difference between the detected values in the two sets of strain gauges opposed to each other in the radial direction of the suspension bush 10, that is, the two sets of the strain gauges 24a and 24b and the strain gauges 24c and 24d. By taking this, the electromotive force due to the strain in the opposite direction of the strain gauge (in the present embodiment, the front-rear direction and the left-right direction of the vehicle) can be obtained with approximately double the value, and the electromotive force due to the strain in the other direction Can be excluded from the detected value.
That is,
By taking the difference between the detected values of the strain gauge 24a and the strain gauge 24b,
(E1 + E2 + E3) − (− E1 + E2 + E3) = 2 * E1
By taking the difference between the detected values of the strain gauge 24c and the strain gauge 24d,
{E4 + (− E5) + E6} − (E4 + E5 + E6) = − 2 * E5
The electromotive force of each is calculated.
(5) By dividing this calculated value by 2 as necessary, only the electromotive force according to the amount of strain in the required direction can be separated and detected with high accuracy. That is, in the present embodiment, the electromotive force E1 is detected by the strain gauge 24a and the strain gauge 24b based on the strain in the vehicle front-rear direction (x direction), and the vehicle left and right are detected by the strain gauge 24c and the strain gauge 24d. An electromotive force: -E5 is detected based on the strain in the direction (y direction). From this detection result, a tensile strain having a magnitude corresponding to the electromotive force E1 is generated in the vehicle front-rear direction, and a compressive strain having a magnitude corresponding to the electromotive force E5 is generated in the vehicle left-right direction. Recognize.
(6) The electromotive force generated in each of the strain gauges 24a to 24d is transmitted to the external computing device 30 through the lead wires 26a to 26d attached to the respective strain gauges 24a to 24d, and based on the detection result of the strain. Thus, the external force acting on the wheel in the vehicle front-rear direction and the left-right direction is estimated by calculation.

  According to the above-described means, since the strain amount of the outer tube fitting 14 having high correlation with the action of the external force on the wheel can be detected with high accuracy in the necessary direction, it is estimated based on the detected value of the strain amount. As for the external force acting on the wheel, it is possible to obtain a highly accurate estimation result very close to the actually applied external force. Further, the estimated value of the external force exerted on the wheel based on the detected strain value is used as a control signal for a vehicle control system such as an antilock braking system, traction control, or vehicle stability control. It is also possible.

  In the acting force measuring apparatus having the structure according to the present embodiment as described above, the strain gauges 24a to 24d are attached to the outer cylindrical metal fitting 14 that is a rigid material, so that it is based on temperature dependence and changes with time. Without being affected by the change in rigidity of the main rubber elastic body 16, the amount of strain corresponding to the external force acting on the wheel can be stably detected, and the external force acting on the wheel can be reliably estimated.

  In the present embodiment, a set of strain gauges 24a and 24b are disposed so as to face each other in the radial direction of the outer tube metal fitting 14, and an outer direction substantially orthogonal to the facing direction of these strain gauges 24a and 24b. Strain gauges 24c and 24d that are opposed to each other are arranged in the radial direction of the tubular fitting 14. Therefore, from the electromotive force generated based on the strain detected by the strain gauges 24a to 24d, only the strain amounts in the respective opposing directions of the strain gauge 24a and the strain gauge 24b and the strain gauge 24c and the strain gauge 24d are accurately separated. Therefore, the external force acting on the wheel can be estimated with high accuracy in the direction that needs to be estimated.

  Further, in this embodiment, the strain gauges 24a to 24d are attached to the vehicle side parts, that is, the suspension parts 32 and the like by attaching the strain gauges 24a to 24d to the outer cylinder fitting 14 constituting the suspension bush 10. Is not necessary. Therefore, it is not necessary to process a large-sized member such as the suspension part 32, and the strain gauge can be easily attached.

  Further, in the present embodiment, sensor mounting recesses 22a to 22d are formed in the outer cylinder fitting 14, and strain gauges 24a to 24d are disposed in the sensor mounting recesses 22a to 22d, respectively. Therefore, the location of the strain gauges 24a to 24d in the outer cylinder fitting 14 is separated from the inner circumference surface of the bush mounting portion 36, and the portion that contacts the inner circumference surface of the bush mounting portion 36 in the outer cylinder fitting 14 is located. As compared with this, it becomes easier to distort, so that reliable and highly accurate detection of strain can be realized by the strain gauges 24a to 24d.

  Furthermore, by forming a plurality of sensor mounting recesses 22a-d with a predetermined length in the circumferential direction so as not to be continuous in the circumferential direction, the outer cylinder can be secured while sufficiently ensuring the direction of strain detection by the strain gauges 24a-d. The mounting strength of the metal fitting 14 to the suspension arm 34 can be ensured and the adverse effect on the vibration isolation performance can be reduced or avoided.

  Further, the sensor mounting recesses 22a to 22d are formed in the vicinity of the center in the axial direction of the outer cylinder fitting 14, and wiring grooves 28a to 28d extending from the lower ends of the sensor mounting depressions 22a to 22d to the lower end of the outer cylinder fitting 14 are formed. Each was formed. Thereby, the upper end part of the outer cylinder metal fitting 14 will be made to contact | abut to the internal peripheral surface of the bush attaching part 36 over a perimeter. Therefore, even when a load in the twisting direction acts on the suspension bush 10, sufficient member strength and mounting strength can be ensured.

  Moreover, in this embodiment, since the outer cylinder metal fitting 14 is located near a wheel compared with the inner cylinder metal fitting 12, the external force which acted on the wheel will act directly. Therefore, the strain amount of the outer cylinder fitting 14 is highly correlated with the external force acting on the wheel, and it is possible to estimate the external force applied to the wheel with high accuracy.

  Furthermore, since the outer cylinder fitting 14 has a larger member size than the inner cylinder fitting 12, it is easy to secure a space for disposing the strain gauge.

  In addition, the strain gauges 24a to d are disposed on the surface opposite to the surface to which the main rubber elastic body 16 is vulcanized and bonded, so that the outer cylinder fitting 14 is vulcanized and bonded to the main rubber elastic body 16 Thus, the strain gauges 24a to 24d can be attached to the outer cylinder fitting 14. Therefore, damage to the strain gauges 24a to 24d due to heat during vulcanization adhesion can be prevented.

  Next, FIGS. 4, 5 and 6 show a suspension bush 38 as a cylindrical rubber mount provided with an acting force measuring apparatus as a second embodiment of the present invention. In addition, in the following description, about the member and site | part substantially the same as 1st embodiment, description is abbreviate | omitted by attaching | subjecting the code | symbol same as 1st embodiment in a figure.

  That is, in the second embodiment, the outer sleeve 40 having a substantially cylindrical shape is disposed on the substantially same central axis as the outer cylinder fitting 14 and is fitted to the outer cylinder fitting 14 in an extrapolated state. ing. By disposing the outer sleeve 40, the outer cylinder fitting 42 as the outer cylinder member in the present embodiment having a double structure in which the outer cylinder fitting 14 is the inner sleeve and the outer sleeve 40 is the outer sleeve is configured. . In the present embodiment, the strain gauges 24a to 24d are sensor mounting recesses 22a formed on the outer peripheral surface of the outer cylindrical metal member 14 between the opposing surfaces of the outer peripheral surface of the outer cylindrical metal member 14 and the inner peripheral surface of the outer sleeve 40. -D.

  In the acting force measuring apparatus having the structure according to the present embodiment, the outer sleeve 40 that is overlapped with the outer peripheral surface of the outer cylinder fitting 14 is fitted, whereby the openings of the sensor mounting recesses 22a to 22d are formed. The outer sleeve 40 substantially covers the cover. Therefore, problems such as breakage of the strain gauges 24a to 24d due to the exposure of the strain gauges 24a to 24d can be avoided, and transportation or storage in a warehouse can be advantageously performed. Further, since the outer circumferential opening of the wiring grooves 28a to 28d is substantially covered with the outer sleeve 40, the lead wires 26a to 26d extending in the wiring grooves 28a to 28d can be easily handled. Thus, the attachment work of the suspension bush 38 to the bush attachment portion 36 can be performed more efficiently. Furthermore, by improving the sealing performance of the strain gauges 24a to 24d and the lead wires 26a to 26d, the detection performance can be stabilized and the durability can be improved.

  Next, FIGS. 7 and 8 show a suspension bush 44 as a cylindrical rubber mount provided with an acting force measuring device as a third embodiment of the present invention. In addition, in the following description, about the member and site | part substantially the same as 1st embodiment, description is abbreviate | omitted by attaching | subjecting the code | symbol same as 1st embodiment in a figure.

  That is, in the present embodiment, the main rubber elastic body 16 is interposed between the opposed surfaces of the inner cylinder fitting 12 and the outer cylinder fitting 46 that are arranged on substantially the same central axis and are spaced apart in the radial direction. The suspension bush is formed by the integrated vulcanized molded product 48 and an acting force measuring sleeve 50 which is formed separately from the integrally vulcanized molded product 48 and is fitted to the integral vulcanized molded product 48 in an extrapolated state. 44 is configured.

  The acting force measuring sleeve 50 is configured such that an inner sleeve 52 and an outer sleeve 54, both of which are substantially cylindrical, are arranged on substantially the same central axis and are overlapped. Sensor mounting recesses 56a to 56d are formed in the inner peripheral surface of the outer sleeve 54 near the center in the axial direction. Further, wiring grooves 58a to 58d extending from the inner peripheral surface of the outer sleeve 54 to the lower end in the axial direction are connected to the lower ends of the sensor mounting recesses 56a to 56d, respectively. The sensor mounting recesses 56a to 56d and the wiring grooves 58a to 58d are formed at a total of four locations in two radial directions substantially orthogonal to each other, and the radially inner openings are substantially covered by the inner sleeve 52. ing. That is, the sensor mounting recesses 56a to 56d and the wiring grooves 58a to 58d are located between the members of the inner sleeve 52 and the outer sleeve 54. The strain gauges 24a to 24d are fixed to the substantially central portions of the sensor mounting recesses 56a to 56d on the inner peripheral surface of the outer sleeve 54, respectively.

  The acting force measuring sleeve 50 is configured such that the outer peripheral surface of the outer tube fitting 46 and the inner peripheral surface of the bush mounting portion 36 in a state in which the integrally vulcanized molded product 48 is disposed with substantially the same central axis with respect to the bush mounting portion 36. And is attached to the integrally vulcanized molded product 48 in an extrapolated state. Thus, the outer cylinder fitting 59 as the outer cylinder member in the present embodiment is constituted by the acting force measuring sleeve 50 and the outer cylinder fitting 46, and the suspension bushing is constituted by the integrally vulcanized molded product 48 and the acting force measuring sleeve 50. 44 is configured. In the present embodiment, the sensor mounting recesses 56a to 56d are not formed in the outer tube fitting 46, and the strain gauges 24a to 24d are not mounted.

  In the suspension bush 44 having the structure according to this embodiment, the amount of strain of the inner sleeve 52 based on the external force acting on the wheel is detected in the acting force measuring sleeve 50 formed separately. Therefore, as the integral vulcanization molded product 48 constituting the suspension bush 44, a conventional product without the strain gauges 24a to 24d can be adopted, and the strain gauges 24a to 24d can be used as the integral vulcanized molded product 48. The strain amount can be detected by the strain gauges 24a to 24d while avoiding the adverse effect on the vibration proof performance due to the disposition to the suspension arm 34, and the disposition work of the suspension bush 44 to the suspension arm 34 is easy. Can be done.

  Although several embodiments of the present invention have been described above, these are merely examples, and the present invention is not construed as being limited to specific descriptions in such embodiments.

  For example, in the first to third embodiments, an example in which the present invention is applied to the suspension bushes 10, 38, and 44 has been described. However, the present invention is applicable to various rubber bushes such as a subframe mount. Applicable.

  In the first and second embodiments, the strain gauges 24a to 24d are attached to the outer peripheral surface of the outer cylinder fitting 14 of the suspension bushes 10 and 38. However, the mounting positions of the strain gauges 24a to 24d are not limited to those of the above embodiment. Specifically, for example, like the suspension bush 60 shown in FIGS. 9 and 10, sensor mounting recesses 64 a to 64 d are formed in the axial central portion of the inner peripheral surface of the inner cylinder fitting 62 as the inner shaft member. The strain gauges 24a to 24d are disposed in the center of the sensor mounting recesses 64a to 64d, and the wirings 26a to 26d are positioned in the wiring grooves 66a to 66d extending below the sensor mounting recesses 64a to 64d. For example, the inner cylinder fitting 62 to which the strain gauges 24a to 24d are attached is arranged on the vehicle body side where the displacement relative to the external computing device 30 is relatively small even when an external force is applied to the wheels. As a result, the relative displacement of the strain gauges 24a to 24d with respect to the external computing device 30 is small and the lead wires 26a to 26d are disconnected. Because it can avoid such it unnecessary to provide extra length in order to prevent breakage of the lead wires 26a-d, facilitates handling of the lead wire 26a-d. In the above description, members and portions that are substantially the same as those in the first to third embodiments are denoted by the same reference numerals in the drawings, and the description thereof is omitted. Further, the strain gauges 24a to 24d can be attached by providing a recess between the main rubber elastic body 16 and the inner cylinder fitting 12 and / or the outer cylinder fitting 14.

  Further, the shape of the sensor mounting recesses 22a to 22d and 52a to 52d is not limited to that of the first to third embodiments. Specifically, for example, the sensor mounting recesses 22a to 22d and 56a to 56d may be formed so as to extend over the entire length in the axial direction of the outer cylinder fitting 14 and the inner sleeve 48.

  Further, the present invention can be suitably used for various types of cylindrical rubber mounts such as a fluid-filled suspension bush.

  Further, in the first to third embodiments, the strain gauges 24a to 24d are positioned in the front-rear direction and the left-right direction of the vehicle under the arrangement state of the suspension bushes 10, 38, 44 with respect to the suspension component 32. However, the arrangement directions of the strain gauges 24a to 24d are appropriately set according to the direction in which the strain detection is required, and are not limited to those of the above-described embodiment.

  In addition, as shown in the first to third embodiments, the strain gauges 24a to 24d are preferably attached in the vicinity of the center in the axial direction. However, the arrangement position in the axial direction depends on the embodiment. It is not limited.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is a cross-sectional view which shows the attachment state to the suspension components of the suspension bush provided with the acting force measuring apparatus as 1st embodiment of this invention. It is a longitudinal cross-sectional view which shows the attachment state to the suspension components of the suspension bush shown by FIG. FIG. 2 is a side view of the suspension bush shown in FIG. 1. It is a cross-sectional view which shows the attachment state to the suspension components of the suspension bush provided with the acting force measuring apparatus as 2nd embodiment of this invention. It is a longitudinal cross-sectional view which shows the attachment state to the suspension components of the suspension bush shown by FIG. FIG. 5 is a side view of the suspension bush shown in FIG. 4. It is a cross-sectional view which shows the attachment state to the suspension components of the suspension bush provided with the acting force measuring apparatus as 3rd embodiment of this invention. FIG. 8 is a longitudinal cross-sectional explanatory view showing a method of assembling the suspension bush shown in FIG. 7 to the suspension component. It is a cross-sectional view which shows the attachment state to the suspension components of the suspension bush provided with the acting force measuring apparatus as another one embodiment of the present invention. FIG. 10 is a longitudinal sectional view showing a state in which the suspension bush shown in FIG. 9 is attached to a suspension component.

DESCRIPTION OF SYMBOLS 10 Suspension bush 12 Inner cylinder metal fitting 14 Outer cylinder metal fitting 16 Main body rubber elastic body 22a-d Sensor mounting recess 24a-d Strain gauge 28a-d Wiring groove 32 Suspension components

Claims (7)

The inner shaft member and the outer cylinder member arranged in an extrapolated state spaced apart on the outer peripheral side of the inner shaft member are elastically formed by a main rubber elastic body disposed between the opposing surfaces in the axis-perpendicular direction of both members. In the cylindrical rubber mount connected to, an acting force measuring device for measuring an external force acting between the inner shaft member and the outer tubular member,
At least one of the inner shaft member and the outer cylinder member has a double structure that is overlapped in the radial direction, and a gap is partially provided between the overlapping surfaces in the radial direction in the double structure. An acting force measuring device for a cylindrical rubber mount, wherein a strain detecting means for detecting a strain amount is mounted on the facing surface . Before SL gap, acting force measuring device according to claim 1, which is a small size than the area of the central angle of 45 degrees in the circumferential direction. The acting force measuring device according to claim 1 or 2 , wherein the gap is formed in the vicinity of an axial center of the inner shaft member and the outer cylinder member. The pre-Symbol inner shaft member with a tubular, by providing a fixation rod to be inserted and fixed to the inner shaft member, 1 to claim there is a double structure in which the inner shaft member are overlapped in the radial direction 4. The acting force measuring device according to any one of 3 above. Provided Bush mounting portion having a fitting hole, by externally secured to the bush mounting portion relative to the outer tubular member, is a double structure in which the outer cylindrical member are overlapped in the radial direction acting force measuring device according to any one of claims 1 to 4 are. According at least one of the previous SL inner shaft member and the outer tubular member, the inner sleeve and the outer sleeve by a double cylinder structure, which is fitted and fixed to each other, which was superimposed double structure in the radial direction Item 4. The acting force measuring device according to any one of Items 1 to 3 . Automotive suspension member by employing the tubular rubber mount as suspension bushing interposed connecting portion of the vehicle body of the (arm or link, includes a rod or the like), according to any one of claims 1 to 6 A suspension mechanism for an automobile, characterized in that an external force acting on the wheels of the automobile from the road surface is obtained using a detection value obtained by the strain detecting means.

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