JP5061082B2 - Joint structure, joint method, and damping force variable damper - Google Patents

Description

  The present invention relates to a joint technology for inserting and connecting a long insertion member to a member to be inserted, and more particularly, to a joint technology applied to a damping force variable damper that attenuates vibration of a vehicle body in a road vehicle or the like.

Various methods have been proposed to easily and reliably connect two parts machined separately. As a known joint technique for preventing high-pressure liquid from leaking to the opposite side when high-pressure liquid exists inside or outside of a hollow insertion member (tubular body) connected to the member to be inserted, There is something like this.
FIG. 4A shows a state before the insertion member 2 and the inserted member 3 are connected in a known joint structure. The distal end portion 2a of the insertion member 2 and the insertion hole 3a of the member to be inserted 3 are processed into a substantially inverted shape, and when connected as shown in FIG. 4B, the peripheral surfaces are in close contact with each other. Composed.

  The C-ring 4 is loosely fitted in a belt-like groove 2b formed on the outer peripheral surface of the distal end portion 2a, and is temporarily reduced in diameter when inserted into the opening of the insertion hole 3a of the member 3 to be inserted. The inner peripheral surface of the member 3 is slidably contacted while being urged. And in the position which reached | attained the annular groove 3b engraved on the inner peripheral surface of the member 3 to be inserted, the C-ring 4 recovers its shape and engages with the annular groove 3b. In this way, the C-ring 4 exhibits the action of preventing the insertion member 2 and the inserted member 3 from being pulled out.

When the O-ring 5 is inserted into the insertion hole 3a of the inserted member 3 in a state where the O-ring 5 is disposed at the reduced diameter portion 2c of the distal end portion 2a of the insertion member 2, the O-ring 5 is pressed and deformed by the contact surface 3c. To do. Thereby, the O-ring 5 seals the gap where the insertion member 2 and the inserted member 3 are in contact with each other, so that the high-pressure liquid filled in the passage 2d does not leak outside.
JP 2002-295756 A

By the way, the belt-like groove 2b in which the C-ring 4 is disposed is a notch provided on the outer peripheral surface of the tip portion 2a formed into a thin cylinder. For this reason, there is a problem that the parts are increased in size and weight due to a safety design for avoiding fatigue fracture due to repeated stress. Furthermore, the process itself of attaching the C-ring 4 to the insertion member 2 becomes a factor that reduces the productivity of the product. In addition, when it is forgotten to attach the C-ring 4, there is a problem that it is difficult to find afterward, and the absence of the C-ring 4 is discovered only after the insertion member 2 is dropped.
An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a joint structure by simply and reliably connecting two parts without using a C-ring 4.

In order to solve the above problems, the present invention provides an insertion member in which a projecting portion formed by extending an outer peripheral portion of a longitudinal tip in the longitudinal direction is formed, and an end of an insertion hole into which the insertion member is inserted, A joint structure for connecting an abutting surface with which a protruding portion abuts and an inserted member including an annular groove including a continuous surface extending radially outward from the abutting surface , wherein the insertion member is a longitudinal A tubular passage penetrating in a direction, and an inner protrusion extending in a longitudinal direction from an opening edge of the tubular passage, and the insertion member is inserted in a state where a seal member is disposed on the inner protrusion. The tubular passage is sealed by press-fitting into a member, deforming the projecting portion in contact with the contact surface, and engaging with the annular groove.
The seal member is held so as to abut on the outer periphery of the inner protrusion, and is separated from the protrusion.

By configuring the invention in this way, the insertion member and the member to be inserted can be connected without using a C-ring. As a result, forgetting to insert the C-ring can be prevented, the number of parts required for connection can be reduced, the work process can be simplified, and productivity can be improved.
The protrusion extends in the axial direction before the insertion member is inserted, but after being inserted into the member to be inserted, the protrusion is plastically deformed radially outward to lock the annular groove. Thereby, the deformation | transformation site | part of the protrusion part latched by the annular groove controls the movement of the said insertion member with respect to the load of an axial direction, and drop-off | omission is prevented.
Further, when the insertion member is inserted into the member to be inserted, since the protrusion does not hinder this insertion, assembly is easy.

  Furthermore, the invention is characterized in that, in the joint structure, the inner peripheral surface of the protruding portion has a shape whose diameter is increased in the insertion direction of the insertion member.

  By configuring the invention in this way, the protruding portion of the insertion member is pressed against the contact surface of the member to be inserted, and the deformation toward the outside in the radial direction is facilitated. Stop function is improved.

  The invention further includes a piston provided with a communicating portion that moves freely while sliding in contact with an inner peripheral surface of a cylinder filled with oil, and that moves the oil partitioned into two, and a tip of the piston. A damping force variable damper comprising a rod that is coupled and penetrates through the cylinder and that is in sliding contact with a side peripheral surface thereof, comprising a joint structure in which the rod is the insertion member and the piston is the inserted member. .

  By configuring the invention in this way, the connection of the rod and the piston in the damping force variable damper that attenuates the vibration of the vehicle body in a road vehicle or the like is based on self-clinching. Thereby, the damping force variable damper can be easily assembled because the rod and piston can be prevented from being pulled out without using the C-ring. Further, since the structure does not use the C-ring, there is no need to provide a belt-like groove on which the C-ring is installed on the rod side, and there is no need to consider fatigue fracture from the belt-like groove in the design.

  Further, the invention is the damping force variable damper, wherein the oil is a magnetic fluid or a magnetorheological fluid containing magnetic particles, and the piston is wound with a coil that applies a magnetic field to the oil that moves through the communication portion. The rod has a hollow structure through which wiring for supplying power to the coil is passed, and the damping force is varied by changing the viscous resistance of the oil in accordance with the power supply.

  By configuring the invention in this way, the insertion member (rod) is connected to the member to be inserted (piston) by self-clinching without providing a belt-like groove. Thereby, the design burden for preventing fatigue breakage is reduced, and the wall thickness of the rod provided with the tubular passage of the coil power supply wiring can be formed thin.

  The present invention provides a joint structure that can easily and reliably connect two parts without using a C-ring.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A shows an insertion member 20A and a member to be inserted 30A before connection in the first embodiment, and FIG. 1B shows a cross section of the joint structure 10A after connection.
In the following, the reference numeral indicating the member according to the first embodiment is attached with the subscript A, and the reference numeral indicating the member according to the second embodiment is attached with the subscript B, but there is no need to distinguish between both. In this case, this subscript is omitted.
The joint structure 10 </ b> A has a structure in which the insertion member 20 is press-fitted into the insertion hole 35 of the inserted member 30 and the both members are connected.

  The insertion member 20 has a longitudinal shape, and is formed with a protruding portion 23 in which the outer peripheral portion at the tip thereof extends in the longitudinal direction. The inner peripheral surface 23a of the protruding portion 23 has a shape whose diameter is increased in the insertion direction of the insertion member 20A, and in this embodiment, has a conical side surface shape. In addition, the cross section of the insertion member 20 is not particularly limited, but can be any of a circular shape and a rectangular indefinite shape.

In the inserted member 30, an annular groove 37 including a contact surface 36 with which the protruding portion 23 contacts and a continuous surface extending radially outward from the contact surface 36 is formed at the end of the insertion hole 35 into which the insertion member 20 is inserted. Has been.
The inner diameter of the insertion hole 35 is set to have a plus tolerance with respect to the outer diameter of the insertion member 20. As a result, the outer peripheral surface of the insertion member 20 is tightly fitted to the inner peripheral surface of the insertion hole 35, and the connection with the member to be inserted 30 becomes more rigid. However, since the coupling by the interference fit depends on the frictional force on the contact surface, when a large force acts in the direction opposite to the inserting direction, the inserted member 30 and the inserting member 20 are displaced from each other or fall off. There is a case.

  As shown in FIG. 1B, the abutting surface 36 is brought into contact with the protruding portion 23 of the insertion member 20 inserted from the direction of the arrow in FIG. To be plastically deformed. Thus, it is preferable that the contact surface 36 has a downward slope toward the radially outer side as illustrated so that the projecting portion 23 is deformed toward the radially outer side. However, as described above, if the inner peripheral surface 23a of the projecting portion 23 has a shape whose diameter is increased in the insertion direction, the projecting portion 23 projects even if such a downward slope is not formed on the contact surface 36. The part 23 is easily deformed toward the radially outer side.

The annular groove 37 is a space which is formed so as to include a continuous surface extending radially outward from the contact surface 36 and accommodates the deformed protrusion 23. The projecting portion 23 that is in contact with the contact surface 36 is deformed outward in the radial direction while being guided by a continuous surface from the contact surface 36. As shown in FIG. 1B, even when a large force is applied in the direction opposite to the insertion direction by firmly locking the deformed protrusion 23 in the annular groove 37, the insertion member 20 and the member to be inserted 30 exhibit a retaining function without being displaced from each other.
Moreover, since the strength of the projecting portion 23 deformed and accommodated in the annular groove 37 is improved by work hardening, the yield value with respect to the stress in the reverse insertion direction is also high.

According to the present invention, when the insertion member 20 and the member to be inserted 30 are rigidly connected, the insertion member 20 is press-fitted into the insertion hole 35 of the member to be inserted 30, and the protruding portion 23 is placed on the contact surface 36 positioned at the end. It only needs to be brought into contact and deformed along the continuous surface and locked into the annular groove 37 (self-clinching).
Thereby, the number of parts required for connection can be reduced, the work process of a joint can be simplified, and productivity can be improved.
Further, since the projecting portion 23 does not interfere with other members when the insertion member 20 and the inserted member 30 are inserted, assembly is facilitated.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a sectional view of a joint structure in which the rod 20B (insertion member 20) and the piston 30B (inserted member 30) in the second embodiment are connected to the damping force variable damper 10B. FIG. 3 shows a cross-sectional structure of the rod 20B and the piston 30B before connection.
In the following description, among the constituent elements of the second embodiment, those common to the configuration of the first embodiment are denoted by the same reference numerals as those in FIG.

The damping force variable damper 10B has a joint structure in which the rod 20B is the insertion member 20 and the piston 30B is the insertion member 30. The damping force variable damper 10B employs a magnetic fluid or a magnetorheological fluid (hereinafter referred to as “MR fluid”) in which magnetic particles are contained in oil as a working fluid, and a cylindrical cylinder 40 filled with the MR fluid. And a piston 30B that partitions the inside of the cylinder 40 into a first chamber P and a second chamber Q, and a rod 20B that is attached so that the piston 30B is slidable in the longitudinal direction of the cylinder 40.
The first chamber P and the second chamber Q communicate with each other through a communication portion 39 provided in the piston 30B, and the MR fluid passes between the first chamber P and the second chamber Q through the communication portion 39. It is movable.

  A trailing arm on the wheel side is connected to the end of the cylinder 40 (not shown) on the side of the second chamber Q, and a damper base (upper part of the wheel house) on the vehicle body side is connected to the end of the cylinder 20B (not shown) on the side of the cylinder 20B. is doing. Then, the vibration picked up by the wheel side while the vehicle is running is attenuated by the viscous resistance of the MR fluid flowing when the piston 30B is displaced inside the cylinder 40 and transmitted to the vehicle body side.

The oil is a magnetic fluid containing magnetic particles or a magnetorheological fluid (MR fluid), and the viscous resistance of the oil is changed by the magnetic field generated by the supplied coil 31 to attenuate the damping force variable damper 10B. The force can be varied.
When a current is passed through the coil 31 through the wiring 31a from a power supply device (not shown), when a magnetic field is applied to the MR fluid flowing through the communicating portion 39, the magnetic particles contained in the MR fluid form chain clusters and communicate with each other. The apparent viscosity of the MR fluid passing through the portion 39 increases. Further, when the magnitude of the current flowing through the coil 31 is controlled, the damping force can be variably controlled according to the magnitude of the magnetic field applied to the MR fluid.

  The two wires 31a for supplying current to the coil 31 are formed in a tubular passage formed in the rod 20B via a groove (not shown) formed in the piston core 38 and a resin sealing portion 35a. 21 is taken out from the other end (not shown) of the rod 20B and connected to a power supply device (not shown).

The description will be continued with reference to FIG.
The piston 30B includes a cylindrical piston core 38 and a piston ring 32 disposed concentrically so that a communication portion 39 having a constant gap is formed between the outer peripheral surface of the piston core 38 and the piston core 38. Side covers 33 and 34 disposed at both ends, respectively.
The piston 30B can freely move in the axial direction of the rod 20B (left-right direction in FIG. 3) while slidingly contacting the inner peripheral surface 40a (see FIG. 2) of the cylinder 40 filled with oil. Furthermore, the piston 30B can partition the inside of the cylinder 40 into a first chamber P and a second chamber Q (see FIG. 2), and can move oil to each other by a communicating portion 39 that passes therethrough. Further, a coil 31 that applies a magnetic field to oil that moves through the communication portion 39 is wound around the piston 30B.

The piston core 38 is preferably made of carbon steel for mechanical structure, which has good workability and is a ferromagnetic material, and has a groove 38a that is engraved with a certain width and a certain depth in the circumferential direction. A coil 31 formed by winding a conducting wire around 38a and an insertion hole 35 formed along the central axis are provided.
The insertion hole 35 is sealed at the end opposite to the side where the rod 20B is inserted by a resin sealing portion 35a made of an insulating resin. A contact surface 36 and an annular groove 37 are formed on the inner peripheral surface of the insertion hole 35 closest to the resin sealing portion 35a.

As the resin sealing portion 35a, a thermosetting resin such as an epoxy resin used as an adhesive is preferably used. According to this, since the adhesiveness (adhesiveness) with the piston core 38 is high, oil can be prevented from entering the tubular passage 21 along the boundary between the piston core 38 and the resin sealing portion 35a. It is because it can do.
Examples of such thermosetting resins include phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane, polyimide, and the like.

Since the piston ring 32 is a member that slides along the inner peripheral surface 40a of the cylinder 40 (see FIG. 2), the frictional sliding performance (for example, wear resistance, etc.) is taken into consideration and the machine is ferromagnetic. Structural carbon steel or the like is preferably used as the material.
The piston ring 32 is coaxially disposed with a communication portion 39 that forms a predetermined distance from the outer periphery of the piston core 38. When the coil 31 is energized, a closed loop magnetic field is formed in the surrounding piston ring 32 and piston core 38. The MR fluid passing through the communication portion 39 forms a chain cluster by this magnetic field, the apparent viscosity increases, and the flow resistance is improved.

The side covers 33 and 34 are preferably made of a non-magnetic material such as aluminum and excellent in workability. The side covers 33 and 34 are provided with holes 33a and 34a communicating with the communication part 39 and holes 33b through which the rod 20B passes. Yes.
The side covers 33 and 34 hold the piston core 38 coaxially from both ends. Further, the outer periphery of the side cover 33 on the side through which the rod 20 </ b> B passes is fitted into the thin molded portion at the edge of the piston ring 32. The opposite side cover 34 is fixed by a separate fixing screw 34b. The outer peripheral surface of the fixed screw 34b is screwed with the inner surface of the thin molded portion at the edge of the piston ring 32, and the distal end of the thin molded portion is crimped inward to prevent rotation.
As a result, the piston core 38 is fixed to the piston ring 32 at a position where the communication portions 39 having a constant interval are formed.
In this way, the communication part 39 communicates the first chamber P and the second chamber Q together with the holes 33a and 34a located at both ends thereof to freely flow the MR fluid.

The end of the rod 20B is connected to the insertion hole 35 of the piston 30B, penetrates the end surface (not shown) of the cylinder 40, and is in sliding contact with the side peripheral surface 22a so as not to leak oil. . This rod 20 </ b> B has a hollow structure in which a tubular passage 21 through which a wire 31 a that supplies power to the coil 31 passes is penetrated in the axial direction.
The rod 20B has a stepped portion 22b that circumscribes the inner peripheral surface of the insertion hole 35 by reducing the outer diameter of the side peripheral surface 22a. Then, the stepped portion of the stepped portion 22b abuts against the edge of the hole 33b of the side cover 33, whereby the amount of insertion of the rod 20B into the piston 30B is defined.

From the tip of the rod 20B, the projecting portion 23 extends in the longitudinal direction from the outer peripheral portion thereof, and is pressed by the contact surface 36 to be deformed and locked in the annular groove 37 (partial enlargement in FIG. 2). Section). As shown in the partially enlarged portion on the left side of FIG. 3, an inclined surface that is enlarged in diameter in the insertion direction is provided on the inner edge of the protruding portion 23. The inclined surface of the projecting portion 23 abuts on the inclined surface of the abutting surface 36 shown in the partial enlarged portion on the right side of FIG. 3 so that the plastic deformation toward the radially outer side of the projecting portion 23 is not delayed. To do.
In addition, the inclined surface provided in the protrusion part 23 and the contact surface 36 is not an essential component, and either one or both may not exist.
Further, an inner protrusion 24 extends in the longitudinal direction from the opening edge of the tubular passage 21 penetrating the rod 20B, and an O-ring 5 as a seal ring is provided. The O-ring 5 is pressed and deformed by the exposed surface of the resin sealing portion 35a to seal the gap.

  As the O-ring 5, those made of rubber such as acrylic rubber or fluorine rubber are preferably used. For example, the oil constituting the MR fluid penetrates between the piston core 38 and the resin sealing portion 35a and leaks into the tubular passage 21, or enters the O-ring 5 along the outer periphery of the rod 20B. Thus, it has a function of preventing leakage into the tubular passage 21.

  The tubular passage 21 guides the wiring 31a from the coil 31 to the external power supply device through the rod 20B, so that the opposite side of the illustration is open to the outside. For this reason, in order to prevent high-pressure oil sealed in the cylinder 40 from leaking from one opening of the tubular passage 21, it is required that the sealing function by the O-ring 5 is sufficiently functioning. The

By configuring the damping force variable damper 10B in this way, the connection between the rod 20B and the piston 30B is based on self-clinching. By this self-clinching mechanism, the effect of preventing the insertion member (rod 20B) from coming off from the member to be inserted (piston 30B) is sufficiently exerted. Thereby, the damping force variable damper 10B can ensure the connection between the rod 20B and the piston 30B without providing the rod 20B with a notch serving as a starting point of fatigue fracture.
This is remarkable in the damping force variable damper 10B that adopts the rod 20B having a thin tube structure by providing the tubular passage 21 that leads the power supply wiring to the outside, and changes the damping resistance by changing the viscous resistance of the MR fluid. The effect is recognized.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment. For example, the object to which the joint structure of the present invention is adopted is not limited to the damping force variable damper, but is a target provided with an insertion member having a longitudinal shape and an insertion hole for inserting the distal end portion of the insertion member. If it connects an insertion member, it can apply widely. Further, the damping force variable damper is not limited to one that changes the viscous resistance of the MR fluid to vary the damping force. The present invention can also be applied to a damping force variable damper that is widely used and includes a piston that moves inside a cylinder and a rod that is connected to the piston and has a longitudinal direction aligned with the moving direction of the piston.

In the joint structure according to the first embodiment of the present invention, (a) shows the inserted member and inserted member before connection, and (b) shows the inserted member and inserted member after connection. It is sectional drawing which shows what employ | adopted the coupling structure of the rod (insertion member) and piston (member to be inserted) after the connection in 2nd Embodiment as the damping force variable damper. The cross-sectional structure before the coupling | bonding of the rod (insertion member) and piston (member to be inserted) employ | adopted in the damping force variable damper of 2nd Embodiment is shown. In the joint structure according to the conventional example, (a) shows the insertion member and inserted member before connection, and (b) shows the insertion member and inserted member after connection.

Explanation of symbols

5 O-ring 10A Joint structure 10B Variable damping force damper 20, 20A Insert member 20, 20B Rod (insert member)
21 Tubular passage 22a Side peripheral surface of rod 23 Protruding part 23a Inner peripheral surface of protruding part 30, 30A Inserted member 30, 30B Piston (member to be inserted)
31 Coil 31a Wiring 32 Piston ring 33 Side cover 35 Insertion hole 35a Resin sealing part 36 Contact surface 37 Annular groove 38 Piston core 39 Communication part 40 Cylinder 40a Inner circumferential surface of cylinder P First chamber Q Second chamber

Claims (6)

An insertion member in which a projecting portion formed by extending the outer peripheral portion of the longitudinal tip in the longitudinal direction is formed;
Connected to the end of the insertion hole into which the insertion member is inserted is an abutting surface on which the protrusion abuts and an inserted member having an annular groove including a continuous surface extending radially outward from the abutting surface A joint structure
The insertion member includes a tubular passage penetrating in the longitudinal direction, and an inner protrusion extending in the longitudinal direction from an opening edge of the tubular passage,
Press-fitting the said insert member in a state in which is disposed a seal member to the inner protrusion on the object to be inserted member, wherein by locking in the annular groove by deforming the protrusion abuts against the abutting surface A joint structure characterized by sealing a tubular passage . The joint structure according to claim 1, wherein the seal member is held so as to be in contact with an outer periphery of the inner protrusion and is separated from the protrusion. 3. The joint structure according to claim 1, wherein an inner peripheral surface of the protruding portion has a shape whose diameter is increased toward an insertion direction of the insertion member. A piston provided with a communicating portion that moves freely while sliding in contact with the inner peripheral surface of a cylinder filled with oil and moves the oil partitioned into two;
A rod having a tip connected to the piston and penetrating through the cylinder and having a side circumferential surface slidably in contact therewith,
The damping force variable damper comprising the joint structure according to any one of claims 1 to 3, wherein the rod is the insertion member and the piston is the inserted member. The oil is a magnetic fluid or magnetic viscous fluid containing magnetic particles,
The piston is wound with a coil that applies a magnetic field to the oil that moves through the communication portion.
The rod has a tubular passage through which a power is supplied to the coil.
The damping force variable damper according to claim 4 , wherein the damping force is varied by changing the viscous resistance of the oil according to the power supply. In a joint method for inserting and connecting an insertion member having a tubular passage penetrating in the longitudinal direction into an insertion hole of a member to be inserted and sealing the tubular passage ,
Holding the seal member on the inner protrusion formed in the longitudinal direction from the opening edge of the tubular passage; and
A step of abutting a protrusion formed by extending an outer peripheral portion of the distal end of the insertion member in a longitudinal direction with a contact surface located at a terminal end of the insertion hole;
Press-fitting the insertion member, deforming the projecting portion along a continuous surface extending radially outward from the contact surface, and engaging with an annular groove including the continuous surface. Joint method.

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