JP4485324B2 - Arm connection structure - Google Patents

Description

  In the present invention, one end of a second arm extending in a direction intersecting with the first arm is connected to a third joint at an intermediate portion of an I-type first arm supported at both ends by a first and second joint. And a connecting structure of arms for inputting a pushing force and a pulling force from a second arm to a first arm via a third joint.

A suspension arm for a vehicle in which an inner end in the left-right direction is connected to a vehicle body via a joint and an outer end in the left-right direction is connected to a knuckle via a joint is known from Patent Document 1 below.
Japanese Patent Laid-Open No. 8-188022

  Incidentally, as shown in FIG. 5, the suspension device 011 extends in the left-right direction of the vehicle body and is connected to the vehicle body 012 and the knuckle 013 by joints 014 and 015, respectively, and the first arm 016 extends in the vehicle body front-rear direction. Let us consider a case in which a second arm 019 connected to the intermediate portion of the vehicle body and the vehicle body 012 by joints 017 and 018, respectively, is provided. When a load in the longitudinal direction of the vehicle body acts on the tire 020 supported by the knuckle 013, the joint 017 that pivotally supports the first arm 016 and the second arm 019 receives a pressing force Fa or a pulling force Fb from the second arm 019. Works. At this time, if the joint 017 is correctly located on the axis of the first arm 016, the torsional moment does not act on the first arm 016 by the pressing force Fa or the pulling force Fb.

  However, the position of the joint 017 is inevitably shifted from the axis of the first arm 016 in the vertical direction and the front-rear direction due to manufacturing errors and design restrictions.

  First, as shown in FIG. 6B, consider a case where the joint 017 is displaced forward and downward from the axis of the first arm 016, for example. When a pulling force Fb toward the front of the vehicle body acts on the second arm 019, a clockwise moment Mb acts on the first arm 016, but the position of the joint 017 moves upward by the rotation of the first arm 016 by the moment Mb. Therefore, the moment Mb gradually decreases and the clockwise twist of the first arm 016 does not increase.

  However, as shown in FIG. 6A, when a pushing force Fa toward the rear of the vehicle body acts on the second arm 019, a counterclockwise moment Ma acts on the first arm 016, but the first Ma due to the moment Ma Since the position of the joint 017 is moved downward by the rotation of the arm 016 (see the chain line), the moment Ma gradually increases, and the first arm 016 is twisted counterclockwise.

  Next, consider a case where the joint 017 is displaced rearward and downward from the axis of the first arm 016, for example. As shown in FIG. 7A, when a pushing force Fa toward the rear of the vehicle body acts on the second arm 019, a counterclockwise moment Mb acts on the first arm 016, but the first arm 016 due to the moment Mb acts. Since the position of the joint 017 is moved upward by the rotation (see the chain line), the moment Mb gradually decreases, and the first arm 016 is not twisted counterclockwise. However, as shown in FIG. 7B, when a pulling force Fb directed toward the front of the vehicle body acts on the second arm 019, a clockwise moment Ma acts on the first arm 016, but the first arm caused by the moment Ma Since the position of the joint 017 moves downward by the rotation of 016, the moment Ma gradually increases, and the clockwise twist of the first arm 016 increases.

  As described above, the case where the position of the joint 017 is shifted forward and downward with respect to the axis of the first arm 016 has been described. However, the position of the joint 017 is forward and upward with respect to the axis of the first arm 016. Even in the case of deviation, there is a problem that the twist of the first arm 016 increases due to the same action.

  The present invention has been made in view of the above circumstances, and when a pressing force and a pulling force are applied to the intermediate portion of the first arm from the second arm connected so as to intersect the first arm, The purpose is to minimize torsional deformation of one arm.

In order to achieve the above object, according to the first aspect of the present invention, both ends of the first I-type arm supported by the support portion via the first and second joints are provided at the first portion. One end of a second arm extending in a direction crossing the arm is connected via a third joint, and a connecting structure of arms for inputting a pushing force and a pulling force from the second arm to the first arm via the third joint. A yoke having a pair of support plates spaced apart in the longitudinal direction of the second arm is provided at at least one end of the first arm, and at least one of the first and second joints is disposed between the pair of support plates of the yoke. When the torsional moment is applied to the first arm around a virtual axis different from the actual axis of the first arm by the pressing force or pulling force input from the second arm , the input is The place that is pushing force To the reaction force from the supporting portion is received by the support plate of the second arm of the yoke, by moving the virtual axis as the center of rotation of the first arm to the second arm, the first 2 force application point of the pushing force input from the arm to the first arm than the imaginary axis is positioned in the counter second arm side, whereas, if the input is a pulling force, anti from the support portion The force is received by the support plate on the side opposite to the second arm of the yoke, and the virtual axis that is the center of rotation of the first arm is moved to the side opposite to the second arm, so that the second arm changes to the first arm. connection structure of the arm, characterized in Rukoto is positioned in the second arm side of the imaginary axis of the force application point of the pulling force input is proposed.

According to the second aspect of the present invention, the both ends extend to the middle portion of the I-type first arm supported by the support portion via the first and second joints in a direction intersecting the first arm. An arm coupling structure in which one end of a second arm is connected via a third joint, and a pushing force and a pulling force are input from the second arm to the first arm via the third joint . joints and is constituted by a rubber bushing joint their axes are arranged in parallel, the two ends of the first arm first, the rewritable connected to the center portion of the second joint, the end of the second arm of the third joint connected to the central portion, the diameter of the first third joint, size comb than the diameter of the second joint, the first arm by pushing force or pulling force input from the second arm, the actual of the first arm Temporary different from the axis When a torsional moment is applied around a general axis, and the input is a pushing force, the third joint is compressed more to the second arm side than the first and second joints, By moving the pressing force application point to the second arm side away from the virtual axis that is the center of rotation of the first arm, the pressing force application point that is input from the second arm to the first arm is obtained. When the input is a pulling force, the third joint is compressed more to the second arm side than the first and second joints. The attractive point of the attractive force input from the second arm to the first arm is moved by moving the attractive point of the attractive force to the second arm side from the virtual axis that is the center of rotation of the first arm. Positioned closer to the second arm than the virtual axis Connection structure of the arm is proposed, which comprises causing.

According to the invention described in claim 3, both ends are extended to the middle portion of the I-type first arm supported by the support portion via the first and second joints in a direction intersecting the first arm. An arm coupling structure in which one end of a second arm is connected via a third joint, and a pushing force and a pulling force are input from the second arm to the first arm via the third joint . the joint is constituted by a rubber bushing joint of substantially the same diameter their axes are arranged in parallel, the rewritable connecting both ends of the first arm to the first, central portion of the second joint, the end of the second arm connected to the central portion of the third joint, a rubber bushing of the third joint first, softer comb than the rubber bush of the second joint, the first arm by pushing force or pulling force input from the second arm, the First When a torsional moment is applied around an imaginary axis different from the actual axis of the beam, and the input is a pushing force, the third joint is made more counter to the first and second joints. By greatly compressing to the second arm side and moving the pressing point of the pushing force to the second arm side away from the virtual axis that is the center of rotation of the first arm, the second arm moves from the first arm to the first arm. In the case where the pressing force input point is positioned on the second arm side opposite to the virtual axis, and the input is a pulling force, the third joint is connected to the first and second joints. Is also greatly compressed toward the second arm side, and the point of attractive force is moved from the second arm side to the second arm side relative to the imaginary axis that is the center of rotation of the first arm, so that the first arm moves from the second arm side. The attractive point of the attractive force input to the virtual Connection structure of the arm, characterized in that of the axis is positioned in the second arm side is proposed.

  The vehicle body 12, the knuckle 13 and the first and second frames 27, 28 of the embodiment correspond to the support portion of the present invention, and the joints 14, 15, 17 of the embodiment are the first to third ( (Rubber bush) Corresponds to the joint.

According to the configuration of the first aspect of the present invention, the second arm extending in the direction intersecting the first arm is provided at the intermediate portion of the I-type first arm supported at both ends by the support portions via the first and second joints. One end is connected via a third joint, and a pushing force and a pulling force are input from the second arm to the first arm via the third joint. In at least one end of the first arm, the longitudinal direction of the second arm A yoke having a pair of support plates spaced apart from each other is provided, and at least one of the first and second joints is disposed between the pair of support plates of the yoke, and the first or second force is input by the second arm. When a torsional moment is applied to an arm around a virtual axis that is different from the actual axis of the first arm, when the input is a pressing force, the reaction force from the support portion is The second arm of the yoke Is received by the support plate, by moving the virtual axis as the center of rotation of the first arm to the second arm side, said force application point of the pushing force which is input from the second arm to the first arm On the other hand, when the input is a pulling force with respect to the virtual axis, the reaction force from the support portion is received by the support plate on the anti-second arm side of the yoke. By moving the virtual axis that is the center of rotation of one arm to the second arm side, the point of the attractive force that is input from the second arm to the first arm is set to be higher than the virtual axis. Runode is located 2 arm side, when the force pressing the second arm is input, counter second arm than the force application point of the pushing force which is input from the second arm to the first arm the imaginary axis The torsional mode applied to the first arm by the pushing force When the pulling force is input from the second arm, the point of the pulling force input from the second arm to the first arm is positioned closer to the second arm than the virtual axis. Thus, by reducing the torsional moment applied to the first arm by the pulling force, the torsional deformation of the first arm can be performed regardless of whether the pushing force or the pulling force is input from the second arm to the first arm. Can be minimized.

According to the second aspect, the first to third di Yointo, their axes are constituted by rubber bush joints arranged in parallel, the two ends of the first arm first, the center of the second joint In addition to connecting, one end of the second arm is connected to the center of the third joint, the diameter of the third joint is made larger than the diameters of the first and second joints, and the pressing force or pull input from the second arm is pulled. When the torsional moment acts on the first arm by a force around a virtual axis different from the actual axis of the first arm, and the input is a pressing force, the third joint is The compression force is greatly compressed toward the second arm side than the first and second joints, and the point of pressing force is moved to the second arm side from the virtual axis that is the center of rotation of the first arm. From the second arm When the pressing force applied to one arm is positioned closer to the second arm than the virtual axis, and the input is a pulling force, the third joint is connected to the first and second joints. By compressing greatly to the second arm side than the joint and moving the point of attractive force to the second arm side from the virtual axis that is the center of rotation of the first arm, the force application point of the pulling force to be input to the first arm than the imaginary axis Ru is positioned on the second arm side.

  Therefore, when a pressing force is input from the second arm, a part of the first and second rubber bush joints is compressed and the virtual axis of the first arm moves to the side opposite to the second arm. The force applied point at which the third rubber bush joint having a diameter larger than that of the second rubber bush joint is compressed is located further to the second arm side than the virtual axis, so that the screw applied to the first arm by the pressing force is applied. The twisting moment can be reduced.

  When a pulling force is input from the second arm, a part of the first and second rubber bush joints is compressed and the virtual axis of the first arm moves to the second arm side. 2 Since the applied force point at which the first rubber bush joint having a diameter larger than that of the rubber bush joint is compressed is located further on the second arm side than the virtual axis, the torsional moment applied to the first arm by the pulling force Can be reduced.

According to the third aspect, the first through third joints, their axes are constituted by rubber bush joint of substantially the same diameter arranged in parallel, the two ends of the first arm first, second joint And connecting one end of the second arm to the center of the third joint, making the rubber bush of the third joint softer than the rubber bush of the first and second joints, and inputting from the second arm When the input is a pushing force when a torsional moment is applied to the first arm around a virtual axis different from the actual axis of the first arm by the pushed or pulled force. The third joint is compressed to the side opposite to the second arm more than the first and second joints, and the point of pressing force is anti-second from the virtual axis that is the center of rotation of the first arm. Moved to the arm side Thus, when the force applied point of the pressing force input from the second arm to the first arm is positioned on the side opposite to the second arm from the virtual axis, on the other hand, when the input is a pulling force, The third joint is greatly compressed to the second arm side than the first and second joints, and the attractive point of the attractive force is moved to the second arm side from the virtual axis that is the center of rotation of the first arm. by the force application point of the pulling force input from the second arm to the first arm than the imaginary axis Ru is positioned on the second arm side.

  Therefore, when a pressing force is input from the second arm, a part of the first and second rubber bush joints is compressed and the virtual axis of the first arm moves to the second arm side. 1. The first rubber bush joint, whose rubber bush is softer than the second rubber bush joint, is positioned on the second arm side further away from the virtual axis, so that the first arm is pressed by the pressing force. The applied torsional moment can be reduced.

  When a pulling force is input from the second arm, a part of the first and second rubber bush joints is compressed and the virtual axis of the first arm moves to the second arm side. Since the force applied point at which the first rubber bush joint is softer than the second rubber bush joint is positioned on the second arm side further than the virtual axis, the twist applied to the first arm by the pulling force. The moment can be reduced.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  First, a first embodiment of the present invention will be described with reference to FIG.

  The suspension device 11 extends in the left-right direction of the vehicle body and has a first arm 16 whose inner and outer ends in the left-right direction are connected to the vehicle body 12 and the knuckle 13 by joints 14 and 15 respectively, and extends in the front-rear direction of the vehicle body and has a rear end at the first end. A second arm 19 is connected to a middle portion of one arm 16 by a joint 17 and a front end is connected to the vehicle body 12 by a joint (not shown).

  The joint 17 that pivotally supports the second arm 19 at the intermediate portion of the first arm 16 includes a ball 16a formed on the first arm 16 and a ball that is provided on the second arm 19 and rotatably holds the ball 16a. It is comprised by the ball joint provided with the holder 19a. The joint 14 that elastically supports the first arm 16 on the vehicle body 12 is constituted by a rubber bush joint in which the inner cylinder 21 and the outer cylinder 22 are connected by a rubber bush 23, and the mounting hole formed in the vehicle body 12 by the outer cylinder 22. A U-shaped yoke 26 that is press-fitted into the inner cylinder 12 and is fastened by a bolt 24 and a nut 25 that penetrate the inner cylinder 21 across both front and rear ends of the inner cylinder 21 is fixed to the end of the first arm 16.

  Accordingly, as shown in FIG. 1A, the front support plate 26a of the yoke 26 of the first arm 16 in which the joint 17 has been pushed rearward by the pressing force Fa input from the second arm 19 has the vehicle body 12 as shown in FIG. Therefore, the axis of the first arm 16 changes from the actual axis L to the virtual axis Lf passing through the front support plate 26a of the yoke 26. As a result, the force point P of the pressing force Fa is located on the rear side of the vehicle body relative to the virtual axis Lf, and even if the force point P of the pressing force Fa is shifted up and down from the virtual axis Lf, The torsional moment acting on the first arm 16 due to the pushing force Fa can be prevented from being excessive (the same state as in FIG. 7A), and the twisting of the first arm 16 can be minimized.

  Further, as shown in FIG. 1B, the first arm 16 having the joint 17 pulled forward by the pulling force Fb input from the second arm 19 has a rear support plate 26b of the yoke 26 from the vehicle body 12. Therefore, the axis of the first arm 16 changes from the actual axis L to the virtual axis Lr passing through the rear support plate 26b of the yoke 26. As a result, the attractive point P of the pulling force Fb is located on the vehicle body front side with respect to the virtual axis Lr, and even if the attractive point P of the pulling force Fb is shifted up and down from the virtual axis Lr, The torsional moment acting on the first arm 16 due to the pulling force Fb can be prevented from being excessive (the same state as FIG. 6B), and the torsion of the first arm 16 can be minimized.

  Here, it is assumed that the yoke 26 provided on the first arm 16 side in this embodiment is provided on the vehicle body 12 side as shown in FIG.

In this case, as shown in FIG. 2 (A), the first arm 16 whose joint 17 is pushed rearward by the pushing force Fa inputted from the second arm 19 is a yoke in which the joint 14 supported thereby is fixed to the car body. In order to receive a reaction force from the rear support plate 26b 'of 26', the axis of the first arm 16 changes from an actual axis L to a virtual axis Lr passing through the rear support plate 26b 'of the yoke 26'. As a result, force application point P of the pressing force Fa will be located on the front side of the vehicle body than the imaginary axis Lr, force application point P of the push force Fa is displaced vertically a little more virtual axis L r Then, the torsional moment acting on the first arm 16 due to the pushing force Fa becomes excessive (the same state as FIG. 6A), and the torsion of the first arm 16 increases.

Further, as shown in FIG. 2B, the first arm 16 having the joint 17 pulled forward by the pulling force Fb input from the second arm 19 has a yoke 26 'fixed to the vehicle body by the joint 14 supported thereby. In order to receive the reaction force from the front support plate 26a ', the axis of the first arm 16 changes from the actual axis L to the virtual axis Lf passing through the front support plate 26a' of the yoke 26 '. As a result, force application point P of the pulling force Fb will be located on the rear side of the vehicle body than the imaginary axis Lf, force application point P of the pulling force Fb is offset vertically a little more virtual axis L f Then, the torsional moment acting on the first arm 16 becomes excessive due to the pulling force Fb (the same state as FIG. 7B), and the torsion of the first arm 16 increases.

  As described above, according to the present embodiment, the torsional deformation of the first arm 16 is minimized even when any of the pushing force Fa and the pulling force Fb is input from the second arm 19 to the first arm 16. be able to.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In this 2nd Example, the description which overlaps by omitting the same code | symbol as 1st Example to the component corresponding to the component of 1st Example is abbreviate | omitted.

  In the second embodiment, both ends of the first arm 16 are connected to the first frame 27 and the second frame 28 by joints 14 and 15, respectively, and one end of the second arm 19 is connected to the intermediate portion of the first arm 16 by the joint 17. The connecting force is used to input the pushing force Fa and the pulling force Fb from the second arm 19 to the first arm 16 through the joint 17.

  Each of the joints 14 and 15 is a rubber bush joint in which an inner cylinder 29 and an outer cylinder 30 are connected by a rubber bush 31, and a U-shaped yoke in which bolts 32 penetrating the inner cylinder 29 are provided at both ends of the first arm 16. The outer cylinder 30 is fastened to the mounting portions 27a and 28a of the first frame 27 and the second frame 28 by press-fitting. The joint 17 is a rubber bush joint in which an inner cylinder 33 and an outer cylinder 34 are connected by a rubber bush 35, and a bolt 36 penetrating the inner cylinder 33 is fastened to a U-shaped yoke 19 b provided at one end of the second arm 19. In addition, the outer cylinder 34 is fixed by press-fitting to an annular mounting portion 16 c formed integrally with the intermediate portion of the first arm 16.

  The directions of the axes of the three joints 14, 15, 17 (the directions of the bolts 32, 32, 36) are parallel, and the diameter D 1 of the joint 17 is set larger than the diameter D 2 of the joints 14, 15.

  As shown in FIG. 3, when the pressing force Fa from the second arm 19 is applied to the first arm 16 via the joint 17, the rubber bushes 31 of the joints 14, 15 at both ends of the first arm 16, In FIG. 31, the points P ′ and P ′ that are eccentric to the right side in the figure are compressed, so that the axis of the first arm 16 moves from the actual axis L to the virtual axis Lr. However, since the diameter D1 of the joint 17 connecting the second arm 19 to the first arm 16 is larger than the diameters D2 and D2 of the joints 14 and 15, the rubber bush 35 of the joint 17 is compressed and the pressing force Fa is reduced. The applied point P moves further to the right from the virtual axis Lr. As a result, the state is the same as in FIG. 7A, and the torsional moment Mb acting on the first arm 16 by the pressing force Fa can be reduced.

  As shown in FIG. 4, when the pulling force Fb from the second arm 19 is applied to the first arm 16 through the joint 17, the rubber bushes 31, 31 of the joints 14, 15 at both ends of the first arm 16. Since the points P ′ and P ′ eccentric to the left in the figure are compressed, the axis of the first arm 16 moves from the actual axis L to the virtual axis Lf. However, since the diameter D1 of the joint 17 connecting the second arm 19 to the first arm 16 is larger than the diameters D2 and D2 of the joints 14 and 15, the rubber bush 35 of the joint 17 is compressed and the pulling force Fb is reduced. The applied force point P moves further to the left than the virtual axis Lf. As a result, the state is the same as in FIG. 6B, and the torsional moment Mb acting on the first arm 16 by the pulling force Fb can be reduced.

  As described above, according to the second embodiment, the torsional deformation of the first arm 16 is minimized even if any of the pushing force Fa and the pulling force Fb is input from the second arm 19 to the first arm 16. Can do.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, in the second embodiment, the diameter D2 of the joints 14 and 15 is set smaller than the diameter D1 of the joint 17. However, as the third embodiment of the present invention, the diameters of the three joints 14, 15, and 17 are Even if the rubber bushes 35 of the joints 17 and 31 are set so as to be softer than the rubber bushes 31 and 31 of the joints 14 and 15, the same effect can be achieved by the same operation as in the second embodiment.

  Further, the arm connection structure of the present invention can be applied to any use other than the suspension device of an automobile.

  The first arm 16 is required to be a substantially straight I-arm, but the second arm 19 is not necessarily a straight shape, and may be a bifurcated shape or a curved shape.

The figure which shows the connection structure of the arm which concerns on 1st Example. The figure which shows the reference example corresponding to 1st Example The figure which shows the connection structure of the arm which concerns on 2nd Example (at the time of input of pushing force) The figure which shows the connection structure of the arm which concerns on 2nd Example (at the time of the input of pulling force) Diagram showing ideal arm connection structure Explanatory diagram of problems of conventional arm connection structure Explanatory diagram of problems of conventional arm connection structure

12 Body (support)
13 Knuckles (supporting part)
14 Joint (1st joint, 1st rubber bush joint)
15 Joint (2nd joint, 2nd rubber bush joint)
16 First arm 17 Joint (third joint, third rubber bush joint)
19 Second arm 26 York 26a Front support plate (support plate)
26b Rear support plate (support plate)
27 First frame (support)
28 Second frame (support)
31 Rubber bush 35 of the first and second joints Rubber bush D1 of the third joint D1 of the third joint D2 Diameter of the first and second joints Fa Pushing force Fb Pulling force L Actual axes Lf and Lr of the first arm The virtual axis Mb of one arm Torsion moment P around the virtual axis

Claims (3)

Both ends cross the first arm (16) at the intermediate portion of the I-type first arm (16) supported by the support portions (12, 13) via the first and second joints (14, 15). One end of the second arm (19) extending in the direction is connected via the third joint (17), and a pressing force (from the second arm (19) to the first arm (16) via the third joint (17) ( Fa) and an arm connecting structure for inputting pulling force (Fb),
At least one end of the first arm (16) is provided with a yoke (26) having a pair of support plates (26a, 26b) spaced apart in the longitudinal direction of the second arm (19), and the pair of support of the yoke (26). Arranging at least one of the first and second joints (14, 15) between the plates (26a, 26b);
A virtual force different from the actual axis (L) of the first arm (16) is applied to the first arm (16) by the pressing force (Fa) or pulling force (Fb) input from the second arm (19). When a torsional moment (Mb) is applied around the axes (Lf 1 , Lr 2 ), if the input is a pushing force (Fa), the reaction force from the support portions (12, 13) The virtual axis (Lf), which is received by the support plate (26a) on the second arm (19) side of (26) and becomes the center of rotation of the first arm (16), is directed to the second arm (19) side. by moving the second arm (19) from the first arm (16) the imaginary axis (Lf) anti second arm than the force application point (P) of the pushing force input (Fa) to (19 ) is positioned on the side, on the other hand, if the input is a pulling force (Fb), the support portion 12, 13) is received by the support plate (26b) on the side opposite to the second arm (19) of the yoke, and the virtual axis (Lr) serving as the center of rotation of the first arm (16) is received. By moving the second arm (19) to the side opposite to the second arm (19), the applied force point (P) of the attractive force (Fb) input from the second arm (19) to the first arm (16) is changed to the virtual axis (Lr). connection structure of the arm, characterized in Rukoto is positioned in the second arm (19) side than). Both ends cross the first arm (16) at the intermediate portion of the I-type first arm (16) supported by the support portions (12, 13) via the first and second joints (14, 15). One end of the second arm (19) extending in the direction is connected via the third joint (17), and a pressing force (from the second arm (19) to the first arm (16) via the third joint (17) ( Fa) and an arm connecting structure for inputting pulling force (Fb),
The first to third joint (14, 15, 17), constituted by their axes rubber bush joint arranged in parallel is, the ends first of the first arm (16), second joint (14, 15 the rewritable connected to the center of), the one end of the second arm (19) connected to the central portion of the third joint (17), third diameter of the joint (17) and (D1) the first, second joint (14, 15) sized comb than the diameter (D2) of
A virtual force different from the actual axis (L) of the first arm (16) is applied to the first arm (16) by the pressing force (Fa) or pulling force (Fb) input from the second arm (19). When the torsional moment (Mb) is applied around the axis (Lf, Lr) and the input is a pressing force (Fa), the third joint (17) is connected to the first and second joints ( 14, 15), which is compressed to the side opposite to the second arm (19), so that the applied force point (P) of the pushing force (Fa) is the virtual axis (the center of rotation of the first arm (16)). By moving the second arm (19) away from Lr), the applied force point (P) of the pressing force (Fa) input from the second arm (19) to the first arm (16) is the virtual On the second arm (19) side with respect to the long axis (Lr), while the input In the case of the pulling force (Fb), the third joint (17) is greatly compressed toward the second arm (19) side than the first and second joints (14, 15), and the pulling force (Fb) By moving the applied point (P) to the second arm (19) side with respect to the virtual axis (Lf) that is the center of rotation of the first arm (16), the first arm (19) is moved from the first arm (19) to the first arm (16). A connecting structure of arms, wherein an attractive point (P) of an attractive force (Fb) input to the arm (16) is positioned closer to the second arm (19) than the virtual axis (Lf) . Both ends cross the first arm (16) at the intermediate portion of the I-type first arm (16) supported by the support portions (12, 13) via the first and second joints (14, 15). One end of the second arm (19) extending in the direction is connected via the third joint (17), and a pressing force (from the second arm (19) to the first arm (16) via the third joint (17) ( Fa) and an arm connecting structure for inputting pulling force (Fb),
The first to third joints (14, 15, 17) are composed of rubber bush joints having substantially the same diameter, the axes of which are arranged in parallel, and both ends of the first arm (16) are the first and second joints. the rewritable connected to the center of the (14, 15), one end of the second arm (19) connected to the central portion of the third joint (17), a rubber bushing (35) of the third joint (17) a 1, soft comb than the rubber bush (31) of the second joint (14, 15),
A virtual force different from the actual axis (L) of the first arm (16) is applied to the first arm (16) by the pressing force (Fa) or pulling force (Fb) input from the second arm (19). When the torsional moment (Mb) is applied around the axis (Lf, Lr) and the input is a pressing force (Fa), the third joint (17) is connected to the first and second joints ( 14, 15), which is compressed to the side opposite to the second arm (19), so that the applied force point (P) of the pushing force (Fa) is the virtual axis (the center of rotation of the first arm (16)). By moving the second arm (19) away from Lr), the applied force point (P) of the pressing force (Fa) input from the second arm (19) to the first arm (16) is the virtual On the second arm (19) side with respect to the long axis (Lr), while the input In the case of the pulling force (Fb), the third joint (17) is greatly compressed toward the second arm (19) side than the first and second joints (14, 15), and the pulling force (Fb) By moving the applied point (P) to the second arm (19) side with respect to the virtual axis (Lf) that is the center of rotation of the first arm (16), the first arm (19) is moved from the first arm (19) to the first arm (16). A connecting structure of arms, wherein an attractive point (P) of an attractive force (Fb) input to the arm (16) is positioned closer to the second arm (19) than the virtual axis (Lf) .

Images