JP4836364B2 - Shock absorber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shock absorber that absorbs an impact (energy) applied to an object, and more particularly to a shock absorber that uses a ball screw and has a high shock absorption rate.
[0002]
[Prior art]
FIG. 1 is a diagram showing the configuration of this type of conventional shock absorber. As shown in the figure, the shock absorber 100 includes a cylinder 101 whose one end is closed, and a piston 102 is slidably accommodated in the cylinder 101 and a fluid such as oil is accommodated in the cylinder 101. . When an impact (energy) in the axial direction is applied to the piston 102, the fluid in the closed end side space 104 divided by the piston 102 flows into the anti-closed end side space 105 through the orifice 103.
[0003]
When the fluid pushed by the piston 102 in the cylinder 101 escapes from the narrow orifice 103 as described above, the pressure difference generated on both surfaces of the piston 102 becomes a resistance force and absorbs the impact (energy) applied to the piston 102. Although illustration is omitted, in order to give a restoring force to the piston 102, a spring is often combined in parallel.
[0004]
The conventional shock absorber has a problem in that the operating stroke of the piston 102 in the cylinder 101 cannot be increased beyond the moving distance of the piston 102, and the impact (energy) absorption efficiency cannot be improved. It was.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above points. By using a ball screw constituted by a screw shaft and a nut member, the operating stroke of the piston in the cylinder is increased, and the impact (energy) absorption efficiency is improved. An object of the present invention is to provide a shock absorber that can be used.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that a first threaded portion that is wound right or left is formed on one end side, and a second threaded portion that is oppositely wound is formed on the other end side. a screw shaft rotatably coupled to a first predetermined object at the end, a first nut member screwed to the first screw portion, a second nut screwed into the second threaded portion and member, comprising a cylinder member, one end of which is closed, so as to function the first nut member is slidably fitted to the piston in the cylinder member, a first nut member functioning as a piston first directly or indirectly pivotably coupled to two of the predetermined object, a second nut member which does not function as a piston fixed to the closed end side of the cylinder member, a first nut member functioning as a piston Applying bias force to apply a predetermined bias force in the axial direction The stage is provided, to fill the fluid in the cylinder member, a first nut member an orifice provided in the first space of the closed end side of the first cylinder member separated by a nut member which functions as a piston The shock absorber is characterized in that the fluid can move between the first space and the second space on the opposite end side .
[0007]
Slidably engaged a first nut member screwed to the first screw portion of the screw shaft which is rotatably connected to the ends as described above with respect to a first predetermined object shea cylinder member A first nut member that functions as a piston is connected to a second predetermined object so as to be swingable directly or indirectly, and a second nut member that does not function as a piston is a cylinder member. As described later in detail, an impact force is applied to the second predetermined object, and when the first nut member functioning as a piston moves in the cylinder, the screw shaft rotates. By this rotation, the second nut member that does not function as a piston moves in a direction opposite to the moving direction of the first nut member that functions as a piston and moves in the cylinder member, so that the first nut member that functions as a piston moves. The operating stroke in the cylinder member becomes large (the moving distance of the cylinder member is added to the moving distance of the first nut member functioning as the piston), and the impact force applied to the second predetermined object with a high absorption rate is obtained. Can be absorbed.
[0008]
According to a second aspect of the present invention, in the shock absorber according to the first aspect, a third space separated from the first space on the closed side in the cylinder member separated by the first nut member functioning as a piston is separated by a partition wall. the space provided in the fluid between the first space and the third space is characterized by providing an orifice to move septum wall.
[0009]
According to a third aspect of the present invention, in the shock absorber according to the second aspect of the present invention, the volume of the third space is changed by an internal fluid pressure.
[0010]
By providing the third space separated from the first space by the partition wall as described above, the operating stroke in the cylinder member of the first nut member functioning as a piston is increased, and the orifice is opened from the first space. Even if the amount of fluid flowing out through it increases, it can be accommodated in the third space.
[0011]
According to a fourth aspect of the present invention, in the shock absorber according to the first, second, or third aspect, the thread grooves of the first screw portion and the second screw portion are rolling element rolling surfaces, and The nut member and the second nut member are provided with an infinite circulation path including a loaded rolling element rolling path corresponding to the rolling element rolling surface, and a plurality of rolling elements are arranged and accommodated in the infinite circulation path. It circulates as the shaft rotates.
[0012]
As described above, the thread grooves of the first screw portion and the second screw portion are rolling element rolling surfaces, and the first nut member and the second nut member are arranged on the rolling element rolling surface. Since an infinite circulation path including a corresponding load rolling element rolling path is provided, an impact force is applied to the second predetermined object, and the first nut member functioning as a piston moves in the cylinder member, whereby the screw shaft is The second nut member that rotates smoothly and does not function as a piston by the rotation of the screw shaft moves smoothly and moves the cylinder member.
[0013]
According to a fifth aspect of the present invention, in the shock absorber according to any one of the first to fourth aspects, the plurality of links having one end pivotally supported by the cylinder member and the other end pivotally supported by the second predetermined object. A mechanism is provided.
[0014]
By providing a plurality of link mechanisms as described above, the movement of the cylinder member and the movement of the first nut member functioning as a piston sliding inside the cylinder member are supported and guided by the link mechanism. Therefore, even if an impact force is applied to the second predetermined object, the shock absorber can absorb the impact with high efficiency without generating vibration.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing the configuration of the shock absorber according to the present invention. In FIG. 2, reference numeral 1 denotes a screw shaft. A first screw portion 2 in which a right-handed or left-handed screw groove is formed is formed on one end side of the screw shaft 1 and the opposite left-handed side is formed on the other end side. Or the 2nd screw part 3 in which the right-handed thread groove was formed is formed. The other end of the screw shaft 1 on which the second screw portion 3 is formed is connected to a first predetermined object (fixed side) 4 via a tilt bearing mechanism 5 so as to be tiltable and rotatable.
[0016]
A cylinder member 6 is closed at one end, and a cylindrical partition wall 14 is disposed in the cylinder member 6, and a first nut member 7 is slidably fitted in the partition wall 14 as a piston. It comes to play a function. The first nut member 7 is screwed into the first screw portion 2 of the screw shaft 1 to form a ball screw to be described later. A second predetermined member is provided via a hollow rod member 8. An object (movable side) 9 is slidably connected via an oscillating support mechanism 10. A second nut member 11 is screwed into the second screw portion 3 of the screw shaft 1, and the nut member 11 is fixed to the closed end side of the cylinder member 6.
[0017]
As shown in FIG. 3, the cylinder member 6 is divided into a first space 12 on the closed end side and a second space 13 on the anti-closed end side by a first nut member 7 that functions as a piston. Further, it is divided into a third space 15 by a cylindrical partition wall 14. The cylinder member 6 is filled with a fluid having a predetermined viscosity such as oil, and an orifice 16 is formed in the first nut member 7, and the fluid moves between the first space 12 and the first space 12 by the movement of the nut member 7. It is possible to move between two spaces 13. An orifice 17 is also formed in the partition wall 14 so that the fluid can move between the first space 12 and the third space 15 by the movement of the first nut member 7.
[0018]
In the first space 12 in the partition wall 14 disposed in the cylinder member 6, a coil spring 21 as a bias force applying means for applying a predetermined bias force to the first nut member 7 toward the non-closed end side. Is provided. Further, an opening 18 is formed in the side wall of the cylinder member 6, and the opening 18 is closed by an elastic plate 19. When the fluid pressure in the third space 15 rises, the fluid passes through the opening 18 and the fluid passes through the elastic plate 19. By pushing outward, the elastic plate 19 expands outward to form a fourth space 20 communicating with the third space 15. In other words, the third space 15 is configured such that the volume changes according to the change of the internal fluid pressure.
[0019]
Reference numerals 36 and 36 denote link mechanisms, and each link mechanism 36 has a configuration in which end portions of a pair of link members 36-1 and 36-2 are pivotally attached to each other. One end of each link mechanism 36 is swingably supported by the swing support mechanism 23 on the base 22 fixed to the second predetermined object 9, and the other end is swung by the swing support mechanism 24 on the outer wall of the cylinder member 6. It is supported freely. FIG. 4 is an AA arrow view of FIG. As shown in the figure, one end of the rod member 8 and one end of the link mechanisms 36 and 36 are respectively attached to the base 22 fixed to the second predetermined object 9 with bolts 22a. It is supported so that it can swing freely. In the above example, two link mechanisms 36 are provided, but three or more link mechanisms 36 may be arranged on the outer periphery of the cylinder member 6 at a predetermined interval.
[0020]
FIG. 5 is a view showing a configuration of the tilt bearing mechanism 5 that rotatably supports the end portion of the screw shaft 1 (as viewed from the arrow BB in FIG. 2). As shown in the figure, the tilt bearing mechanism 5 has a ball bearing seat 27 fixed to a base 25 fixed to a first predetermined object 4 with a bolt 26 with a bolt 29, and is fixed to the ball bearing seat 27 at one end of the screw shaft 1. The spherical body 28 is rotatably fitted.
[0021]
Note that the tilt bearing mechanism 5 is not limited to the above configuration, and as shown in FIG. 6, a bearing 30 is fixed to one end of the screw shaft 1, and a ball bearing seat 31 is fixed to the bearing 30. A configuration may be adopted in which a spherical body 32 fixed to the first predetermined object 4 is rotatably fitted to the ball bearing seat 31.
[0022]
7 to 9 are views showing a configuration example of a ball screw constituted by a second screw portion 3 and a second nut member 11 formed on one end side of the screw shaft 1. The thread groove of the second screw portion 3 formed on one end side of the screw shaft 1 is a ball rolling groove 3a, and the inner peripheral surface of the nut member 11 is subjected to load rolling facing the ball rolling groove 3a. A running groove 11a is formed. A large number of balls 33 are interposed between the ball rolling groove 3a and the load rolling groove 11a so as to roll.
[0023]
A load rolling path is formed between the ball rolling groove 3 a of the second screw portion 3 of the screw shaft 1 and the load rolling groove 11 a of the nut member 11. Two return pipes 34 are fitted to the nut member 11. The return pipe 34 connects one end and the other end of the load rolling groove 11a to form a no-load passage. Both sides of the return pipe 34 are bent and are inserted into the load rolling path with an interval of several pitches. The return pipe 34 is fixed to the nut member 11 by a pipe presser 35.
[0024]
The nut member 11 has a substantially cylindrical shape, and is provided with a flange 11 b on its end face for fixing to the closed end of the cylinder member 6. On the inner peripheral surface of the nut member 11, the load rolling groove 11 a that faces the ball rolling groove 3 a of the second screw portion 3 of the screw shaft 1 is formed as described above. The load rolling groove 11a has a cross-sectional shape where two different arcs intersect, that is, a Gothic arch shape. The nut member 11 is formed with a flat surface portion 11c whose upper surface is partially flattened. The flat portion 11c is provided with four return pipe fitting holes 11d into which both sides of the return pipe 34 are inserted. The return pipe fitting hole 11d extends into the load rolling groove 11a.
[0025]
As shown in FIG. 9, the leg portions 34 a and 34 b of the return pipe 34 are arranged so as to be inclined according to the lead angle of the screw shaft 1. . The balls 33 are scooped up by the legs 34a and 34b while maintaining the lead angle direction of the screw shaft 1, that is, the traveling direction. Therefore, it is not necessary to change the direction in the leg portions 34a and 34b, and it is possible to prevent a strong shock from being applied to the leg portions 34a and 34b. Further, the balls 33 are scooped up on the legs 34a, 34b while maintaining the traveling direction, so that they are scooped up in a balanced manner on both sides without being shifted to one side of the cut end.
[0026]
When the nut member 11 is moved in the axial direction of the screw shaft 1, the screw shaft 1 rotates, and the balls 33 that roll while receiving the axial load in the circumferential direction in the ball rolling groove 3 a are formed on the legs 34 a of the return pipe 34. Crawled at the tip. The scooped balls 33 circulate in the return pipe 34. Then, the balls 33 are returned to the ball rolling groove 3a from the leg portions 34b having a few pitch intervals and circulated.
[0027]
Although illustration is omitted, the configuration of the ball screw including the first screw portion 2 formed on one end side of the screw shaft 1 and the nut member 7 has a partition wall in which the nut member 7 is disposed in the cylinder member 6. 14 is configured so as to slide in the axial direction of the screw shaft 1, and the rest of the configuration is substantially the same as in the above example, and the description thereof is omitted.
[0028]
The operation of the shock absorber having the above configuration will be described below. As shown in FIG. 2, when an impact force F acts on the second predetermined object 9 toward the first predetermined object 4, the rod member 8 and the first nut member 7 are pushed in the direction of arrow C, and the coil spring 21. It moves in the axial direction against the bias force. The axial movement of the first nut member 7 causes the screw shaft 1 to rotate in the arrow D direction. By the rotation of the screw shaft 1, the second nut member 11 moves in the direction of arrow E (the direction opposite to the direction of arrow C). If the screw pitches of the first screw part 2 and the second screw part 3 are the same, the first nut member 7 and the second nut member 11 move in the opposite directions at the same speed and the same distance. Thus, the operating stroke of the first nut member is twice the moving distance of itself.
[0029]
Due to the movement of the first nut member 7 in the partition wall 14, the fluid in the first space 12 moves to the second space 13 (see FIG. 3) and the third space 15 through the orifices 16 and 17. . Thereby, the impact force (energy) F acting on the second predetermined object 9 is absorbed. That is, the first nut member 7 and the second nut member 11 move in the opposite directions in the axial direction, and the operating stroke of the first nut member 7 in the cylinder member 6 (inside the partition wall 14) is It becomes a value obtained by adding the moving distance of the second nut member 11 (the moving distance of the cylinder member 6) to its own moving distance, and effectively absorbs the impact force F acting on the second predetermined object 9.
[0030]
In the above example, a cylindrical partition wall 14 is arranged in the cylinder member 6, and the partition wall 14 forms a third space 15 that is isolated from the first space 12 and the second space 13. The third space is not necessarily required. The partition 14 in the cylinder member 6 is removed, and the first space 12 and the second space 13 that are partitioned by the first nut member 7 in the cylinder member 6. It is good only as well.
[0031]
【The invention's effect】
As described above, according to the invention described in each claim, the following excellent effects can be obtained.
[0032]
According to the invention described in claim 1, the first nut member screwed to the first screw portion of the freely linked threaded shaft end portion relative to the first predetermined object cylinder member A first nut member that functions as a piston is slidably fitted and slidably connected to a second predetermined object so as to be swingable directly or indirectly, and does not function as a piston . By fixing the nut member 2 to the closed end side of the cylinder member, the operation stroke in the cylinder member of the first nut member functioning as a piston is increased, and a shock absorber having a high impact force absorption rate can be provided.
[0033]
According to the second or third aspect of the invention, by providing the third space separated from the first space by the partition wall, the operating stroke in the cylinder member of the first nut member functioning as a piston is increased. Thus, even if the amount of fluid flowing out from the first space through the orifice increases, it can be accommodated in the third space, so that a shock absorber that can sufficiently absorb even a large impact force can be provided.
[0034]
According to invention of Claim 4, the thread groove of the 1st thread part and the 2nd thread part serves as a rolling element rolling surface, and the 1st nut member and the 2nd nut member are Since an infinite circulation path including a load rolling element rolling path corresponding to the rolling element rolling surface is provided, when an impact force is applied to the second predetermined object, the first nut member that functions as a piston and a piston function A shock absorber capable of smoothly moving the second nut member not to absorb and efficiently absorbing the impact force can be provided.
[0035]
According to the fifth aspect of the present invention, by providing a plurality of link mechanisms, the movement of the cylinder member and the movement of the first nut member functioning as a piston that slides in the cylinder member are performed by the link mechanism. Since it is supported and guided, it is possible to provide a shock absorber capable of absorbing this impact with high efficiency without generating vibration even if an impact force is applied to the second predetermined object.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of a conventional shock absorber.
FIG. 2 is a diagram showing a configuration example of a shock absorber according to the present invention.
FIG. 3 is a diagram showing a configuration example of a cylinder member portion of a shock absorber according to the present invention.
4 is an AA arrow view of FIG. 2;
5 is a BB arrow view of FIG.
FIG. 6 is a diagram showing a configuration example of a shock absorber bearing mechanism according to the present invention.
FIG. 7 is an external view showing a configuration example of a ball screw of a shock absorber according to the present invention.
FIG. 8 is an external view showing a configuration example of a nut member of a ball screw of the shock absorber according to the present invention.
FIG. 9 is a diagram showing a configuration example of a screw shaft of a ball screw and a return pipe of a shock absorber according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screw shaft 2 1st thread part 3 2nd thread part 4 1st predetermined object (fixed side)
5 tilting bearing mechanism 6 cylinder member 7 first nut member 8 rod member 9 second predetermined object (movable side)
10 swing support mechanism 11 second nut member 12 first space 13 second space 14 partition 15 third space 16 orifice 17 orifice 18 opening 19 elastic plate 20 fourth space 21 coil spring 22 base 23 swing Support mechanism 24 Swing support mechanism 25 Base 26 Bolt 27 Ball bearing seat 28 Spherical body 29 Bolt 30 Bearing 31 Ball bearing seat 32 Spherical body 33 Ball 34 Return pipe 35 Pipe retainer 36 Link mechanism

Claims (5)

A right-handed or left-handed first threaded portion is formed on one end side, and a second threaded portion on the opposite end is formed on the other end side. The other end is rotatably connected to the first predetermined object. And a first nut member screwed into the first screw part, a second nut member screwed into the second screw part, and a cylinder member closed at one end. , so as to function as a slidably fitted piston said first nut member before Symbol cylinder member, directly or indirectly a first nut member that functions as the piston relative to the second predetermined object a swingably connected, the second nut member which does not function as the piston is fixed to the closed end side of the cylinder member, a predetermined biasing force in the axial direction relative to the first nut member functioning as said piston Bias force applying means for applying To fill fluid into the cylinder member, the orifice in the first nut member functioning as a piston provided anti with the first first space closed end side in the cylinder member separated by a nut member A shock absorber characterized in that the fluid can move between the second spaces on the closed end side. The shock absorber according to claim 1.
The third space separated by closed side of the first space and the partition wall of the first in the cylinder member separated by a nut member that functions as the piston is provided, the said in the partition wall first space the A shock absorber comprising an orifice through which a fluid moves between three spaces. The shock absorber according to claim 2,
The third space is configured so that the volume thereof is changed by an internal fluid pressure. The shock absorber according to claim 1, 2 or 3,
The thread grooves of the first screw portion and the second screw portion are rolling element rolling surfaces, and the first nut member and the second nut member correspond to the rolling element rolling surface. An infinite circulation path including a loaded rolling element rolling path is provided, and a plurality of rolling elements are arranged and accommodated in the infinite circulation path and circulates according to the rotation of the screw shaft. The shock absorber according to any one of claims 1 to 4,
A shock absorber comprising a plurality of link mechanisms having one end pivotally supported by the cylinder member and the other end pivotally supported by the second predetermined object.

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