Pressing device and pressing method

Abstract

To make it possible that when press-fitting a pillar body with a buffer member arranged on an outside surface thereof into a cylindrical member, these members are reliably mounted so as to have an initial positional relationship regardless of a magnitude of a coefficient of friction between these members.SOLUTION: A press-fitting device comprises: a first support part which supports a pillar body from below in a posture where an axis of the pillar body, on an outside surface of which a buffer member is arranged, is in a vertical direction; a second support part which so supports a cylindrical member as to be coaxial with the pillar body above the pillar body; and a press-fitting part which so makes the pillar body and the cylindrical member as to approach in the vertical direction, and press-fits a set of the pillar body and the buffer member into the cylindrical member. In this device, an abutment jig, which has a contact surface facing a lower end surface of the buffer member in the vertical direction between an inner peripheral surface of the cylindrical member and the outside surface of the pillar body and is so configured as not to interfere with either the cylindrical member or the second support part from start to end of press-fitting, is provided so that the contact surface is positioned at a prescribed position included in a range from the position of the lower end surface of the buffer member in the vertical direction before press-fitting to the position of the lower end surface of the pillar body in the vertical direction.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a press-fitting device and a press-fitting method. Specifically, the present invention relates to a device and a method for press-fitting a columnar body having a buffer member disposed on its outer surface into a cylindrical member and holding the columnar body and the buffer member at a desired position inside the cylindrical member.

Background Art

[0002] Conventionally, from the viewpoint of global environmental protection, it has been an essential requirement for vehicles powered by internal combustion engines to be equipped with a catalytic converter. As a manufacturing method of a catalytic converter, as shown in FIG. 15, a ceramic buffer mat 300 as a buffer member is wound around the outer periphery of a columnar catalyst carrier (columnar body) 200, and these are accommodated in a cylindrical member 400. In this case, a method of press-fitting (press-fitting method) while compressing the buffer mat 300 from one opening of the cylindrical member 400 is generally used. More specifically, an annular guide jig 600 is fitted to one opening of the cylindrical member 400, and the catalyst carrier 200 and the buffer mat 300 are press-fitted into the hollow portion of the cylindrical member 400 by a pressing member 500 via the guide jig 600. According to such a method, the catalyst carrier is held at a predetermined position inside the cylindrical member 400 by the restoring force of the buffer mat 300 compressed and sandwiched between the catalyst carrier 200 and the cylindrical member 400.

[0003] By the way, in the above manufacturing method, for example, when the catalyst carrier 200 is press-fitted, the axial center of the catalyst carrier 200 may be inclined with respect to the axial center of the cylindrical member 400, or even if the axial center of the catalyst carrier 200 is parallel to the axial center of the cylindrical member 400, it may be eccentric with respect to the axial center of the cylindrical member 400 (a deviation occurs in the left-right direction in FIG. 15). In such a case, there is a risk that the corners of the catalyst carrier 200 or the buffer mat 300 may be damaged, the buffer mat 300 may peel off, and in the worst case, the catalyst carrier 200 and / or the buffer mat 300 may be damaged. Thus, in order to obtain an appropriate press-fitting (interior installation) state in the above manufacturing method, it is necessary to perform press-fitting in a state where the cylindrical member 400, the pressing member 500, and the catalyst carrier 200 are all arranged coaxially.

[0004] However, in order to surely arrange all of the cylindrical member 400, the pressing member 500, and the catalyst carrier 200 coaxially, a special device, jig, or even a measurement system is required instead of the conventional manual arrangement work, which may lead to an increase in cost and cycle time. Further, even if the above arrangement is achieved once, the arrangement may collapse due to the biased compression of the buffer mat 300 by the self-weight of the catalyst carrier 200 during the press-fitting process.

[0005] Therefore, in the relevant technical field, as shown in FIG. 16, a columnar catalyst carrier 200 with a buffer mat 300 wound around its outer surface is placed on a support jig 700 such that its axis is located on the vertical line VL and is movable in the horizontal direction, and a cylindrical member 400 placed on a guide jig 600 having a tapered portion 600a whose cross-sectional area of the hollow guide portion gradually increases downward is externally fitted to the catalyst carrier 200 from above together with the guide jig 600, so that the buffer mat 300 is compressed by the tapered portion of the guide jig 600 while the catalyst carrier 200 and the buffer mat 300 are press-fitted into the cylindrical member 400 (see, for example, Patent Document 1).

[0006] According to the above method, in the process of press-fitting the catalyst carrier 200 into the cylindrical member 400, since the buffer mat 300 is axially compressed by the tapered portion of the guide jig 600, it is possible to maintain all of the catalyst carrier 200, the cylindrical member 400, and the guide jig 600 in a coaxial arrangement. Therefore, the catalyst carrier 200 and the buffer mat 300 can be smoothly and appropriately press-fitted into the cylindrical member 400 without the need for special devices, jigs, measurement systems, etc., and the desired press-fitted state can be surely achieved.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the press-fitting device according to the prior art as described above and the press-fitting method using the press-fitting device (hereinafter, may be referred to as "conventional device" and "conventional method" respectively), the cylindrical member, the buffer member, and the columnar body may not be mounted so as to have a desired positional relationship in the axial direction. Specifically, for example, as shown in FIG. 17, the columnar body 200 with the buffer mat 300 wound around the outer surface is pressed into the inside of the cylindrical member 400 from the lower side to the upper side toward the drawing, and should have the positional relationship exemplified in (a). However, due to the friction with the inner peripheral surface of the cylindrical member 400, the buffer mat 300 may shift as exemplified in (b) and protrude further below the lower end surface of the columnar body 200. When the buffer mat 300 protrudes below the lower end surface of the columnar body 200 in this way, for example, it may lead to problems such as a decrease in the holding force of the columnar body 200 inside the cylindrical member 400 due to the restoring force of the buffer mat 300 and an unintended interference by the lower end portion of the buffer mat 300 in a device including an assembly in which the columnar body 200 with the buffer mat 300 disposed on the outer surface is pressed into the inside of the cylindrical member 400.

[0009] The above phenomenon is likely to occur when the friction coefficient (static friction coefficient and / or kinetic friction coefficient) between the columnar body 200 and the buffer member 300 (see the portion α surrounded by the broken line in FIG. 17(a)) is lower than the friction coefficient between the buffer member 300 and the cylindrical member 400 (see the portion β surrounded by the broken line in FIG. 17(a)).

[0010] As described above, in this technical field, when press-fitting a columnar body with a buffer member disposed on the outer surface into the inside of a cylindrical member, a technique that can surely mount these so as to have a desired positional relationship is required regardless of the magnitude relationship of the friction coefficients between the columnar body, the buffer member, and the cylindrical member.

Means for Solving the Problems

[0011] As a result of intensive research, the inventor of the present invention has found that by providing a contact jig that contacts a buffer member disposed on the outer surface of the column body in the press-fitting process, it is possible to reduce the displacement of the buffer member caused by press-fitting and solve the above problems.

[0012] Specifically, the press-fitting device according to the present invention (hereinafter, may be referred to as "the device of the present invention") is a press-fitting device including a first support portion, a second support portion, and a press-fitting portion. The first support portion has a support base that supports the column body from below in a posture in which the axial direction of the column body having the buffer member disposed on the outer surface is parallel to the vertical direction. The second support portion supports the cylindrical member in a posture coaxial with the column body above the column body supported by the first support portion. The press-fitting portion drives the column body supported by the first support portion and the cylindrical member supported by the second support portion to approach each other in the vertical direction to perform press-fitting of the set of the column body and the buffer member into the cylindrical member.

[0013] The device of the present invention further includes a contact jig. The contact jig is a member having a contact surface that is a surface facing the lower end surface of the buffer member in the vertical direction within a region between the inner peripheral surface of the cylindrical member and the outer surface of the column body in a vertical projection onto a horizontal plane. The contact jig is configured so as not to interfere with either the cylindrical member or the second support portion at least during the period from the start to the end of press-fitting, and is disposed such that the contact surface is located at a predetermined position included in a first range. The first range is a range from a first position that is the position in the vertical direction of the lower end surface of the buffer member before press-fitting to a second position that is the position in the vertical direction of the lower end surface of the column body.

[0014] The contact jig may be arranged such that the contact surface is fixed at a predetermined position included in the first range, i.e., the third position. Conversely, the contact jig may be configured such that the contact surface is movable forward and backward in the vertical direction over a second range, which is a range from the third position to the fourth position, and the contact surface is arranged to be located at the third position when press-fitting is started. The fourth position is a position included in the first range and located below the third position. In the latter case, the device of the present invention further includes a biasing portion that drives the contact jig so that the contact surface is biased upward, and the biasing portion is configured such that the biasing force is smaller than the pressing force during at least a part of the period from the time when the lower end surface of the buffer member contacts the contact surface to the time when press-fitting ends. Here, the biasing force is the force applied upward to the contact surface by the biasing portion, and the pressing force is the force with which the lower end surface of the buffer member presses the contact surface downward. Alternatively, the device of the present invention may further include a driving portion that drives the contact jig so that the contact surface moves at a predetermined speed over the second range. In addition to the above, the support base may be configured such that the support surface, which is the top surface of the support base, is tiltable within a predetermined angle range with respect to the horizontal plane.

[0015] On the other hand, the press-fitting method according to the present invention (hereinafter may be referred to as "the method of the present invention") is a press-fitting method in which a columnar body with a buffer member disposed on its outer surface is press-fitted into a cylindrical member using a press-fitting device. The press-fitting device used in the method of the present invention is the press-fitting device (the device of the present invention) according to the present invention described above. The method of the present invention includes the first to fourth steps listed below.

[0016] First step: Dispose a buffer member on the outer surface of the columnar body. Second step: Support the columnar body with the buffer member disposed on its outer surface by a first support portion in a posture where the axial direction of the columnar body is parallel to the vertical direction. Third step: Support the cylindrical member by a second support portion in a posture coaxial with the columnar body above the columnar body supported by the first support portion. Step 4: The column body supported by the first support part and the cylindrical member supported by the second support part are driven by a press-fitting part so as to approach each other in the vertical direction, and the assembly of the column body and the buffer member is press-fitted into the inside of the cylindrical member.

[0017] Furthermore, in the method of the present invention, even when the buffer member moves downward with respect to the column body as the press-fitting is performed, the contact between the lower end surface of the buffer member and the contact surface prevents the lower end surface of the buffer member from moving downward beyond the contact surface.

Advantages of the Invention

[0018] As described above, in the device of the present invention, the contact jig is disposed such that the contact surface is located at a position included in the range (first range) from the position (first position) in the vertical direction of the lower end surface of the buffer member before the press-fitting to the position (second position) in the vertical direction of the lower end surface of the column body. Therefore, when the buffer member moves downward with respect to the column body as the press-fitting is performed, the lower end surface of the buffer member can contact the contact surface at a position included in the first range.

[0019] The contact surface may be fixed at a third position which is a predetermined position included in the first range. In this case, the third position which is the position of the contact surface in the vertical direction can be determined such that the column body, the buffer member, and the cylindrical member are in the desired positional relationship. Alternatively, the contact surface may be movable forward and backward in the vertical direction over a range (second range) from the third position to a fourth position included in the first range and located below the third position. In this case, the contact surface is not located below the second position which is the lower limit of the first range, and the fourth position which is the position of the contact surface in the vertical direction when the contact surface is located at the lowest position can be determined such that the column body, the buffer member, and the cylindrical member are in the desired positional relationship.

[0020] As described above, in the apparatus of the present invention, even when the buffer member moves downward with respect to the columnar body during press-fitting, the downward movement of the buffer member can be blocked or reduced by the contact between the lower end surface of the buffer member and the contact surface of the contact jig. As a result, it is possible to reliably prevent the lower end surface of the buffer member from moving downward beyond a desired position included in the first range.

[0021] That is, according to the apparatus of the present invention, when press-fitting a columnar body having a buffer member disposed on its outer surface into the inside of a cylindrical member, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be reliably mounted so as to have a desired positional relationship, and the columnar body can be held at a predetermined position inside the cylindrical member.

[0022] Furthermore, in the apparatus of the present invention, as described above, the support base may be configured such that the support surface, which is the top surface of the support base, is tiltable within a predetermined angle range with respect to the horizontal plane. In this case, even when the lower end surface of the columnar body is not horizontal (not perpendicular to the axis of the columnar body), the support surface can be inclined according to the angle of the lower end surface of the columnar body, and surface contact with the lower end surface of the columnar body can be achieved. Therefore, it is possible to reduce the risk of problems such as breakage of the columnar body due to local contact between the lower end surface of the columnar body and the support surface, leading to stress concentration and the like.

[0023] Needless to say, the method of the present invention, which is a press-fitting method using the apparatus of the present invention capable of achieving the above-described effects, can also achieve the same effects as described above.

[0024] Other objects, other features, and attendant advantages of the present invention will be readily understood from the description of each embodiment of the present invention described with reference to the following drawings.

Brief Description of the Drawings

[0025]

Figure 1

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Figure 15

Figure 16

Figure 17

Best Mode for Carrying Out the Invention

[0026] 《First Embodiment》 Hereinafter, a press-fitting device according to the first embodiment of the present invention (hereinafter, may be referred to as the "first device") will be described with reference to the drawings.

[0027] 〈Configuration〉 The first device is a press-fitting device including a first support portion, a second support portion, and a press-fitting portion. The first support portion has a support base that supports a columnar body from below in a posture where the axial direction of the columnar body having a buffer member disposed on its outer surface is parallel to the vertical direction. Typically, the support base is a pedestal-shaped member having a top surface corresponding to the lower end surface of the columnar body. The second support portion supports a cylindrical member in a coaxial posture above the columnar body supported by the first support portion. Naturally, the second support portion should be configured to be able to hold the lower opening of the cylindrical member facing the combination of the columnar body and the buffer member and not to prevent the press-fitting of the combination of the columnar body and the buffer member into the inside of the cylindrical member. As a specific example of the second support portion, for example, a guide jig or the like provided in the press-fitting device (hereinafter, may be referred to as the "conventional device 1") described in Patent Document 1 mentioned above can be cited.

[0028] The press-fitting part drives the columnar body supported by the first support part and the cylindrical member supported by the second support part to approach each other in the vertical direction, and presses the combination of the columnar body and the buffer member into the cylindrical member. The configuration of the press-fitting part is not particularly limited as long as it can drive the columnar body supported by the first support part and the cylindrical member supported by the second support part to approach each other in the vertical direction and press the combination of the columnar body and the buffer member into the cylindrical member. Typically, the press-fitting part presses the cylindrical member downward from the upper side (opposite to the columnar body) of the cylindrical member by a pressing member driven by an actuator such as a hydraulic cylinder, so that the columnar body supported by the first support part and the cylindrical member supported by the second support part can approach each other in the vertical direction. Alternatively, the press-fitting part presses the first support part upward from the lower side (opposite to the columnar body) of the support base by a pressing member driven by an actuator such as a hydraulic cylinder, so that the columnar body supported by the first support part and the cylindrical member supported by the second support part can approach each other in the vertical direction.

[0029] As a specific example of an apparatus including an assembly in which a columnar body having a buffer member disposed on its outer surface as described above is press-fitted into a cylindrical member, for example, an exhaust gas treatment apparatus such as a catalytic converter and a diesel exhaust gas treatment apparatus can be mentioned.

[0030] In the case of a catalytic converter, the columnar body corresponds to, for example, a catalyst carrier made of a ceramic honeycomb structure. Further, the catalytic converter may be an electrically heated catalyst (EHC) which is a purification member provided with a heating element that generates heat by energizing through a pair of electrodes to heat the exhaust gas purification catalyst. In this case, the columnar body may be the heating element. On the other hand, in the case of a diesel exhaust gas treatment apparatus, the columnar body corresponds to a diesel particulate filter (DPF). The shapes of these columnar bodies are generally cylindrical or columnar, but may be, for example, elliptical columnar or prismatic.

[0031] The buffer member is also referred to as a "buffer mat" or a "holding member". Specific examples of the material forming the buffer member include, for example, inorganic fibers such as alumina-based fibers and alumina-silica-based fibers, and those obtained by adding a resin as a binder to such inorganic fibers. Specific examples of the resin used as the binder include, for example, acrylic rubber, nitrile rubber, polyvinyl alcohol, and acrylic resin. Also, thermally expandable vermiculite can be used as the buffer member. Alternatively, depending on the application of the above assembly, a wire mesh formed by braiding metal wires or the like can also be used as the buffer member. Further, a plurality of types of buffer members made of different materials may be used in combination, and for example, an annular retainer or the like may be used in combination with the buffer member.

[0032] The cylindrical member is also referred to as an "outer cylinder" or a "housing" or a "case", and is typically formed of a metal such as stainless steel. The shape of the cylindrical member (for example, inner diameter, outer diameter, length, wall thickness of the tube, etc.) is determined such that a columnar body with a buffer member disposed on its outer surface can be accommodated inside, and the buffer member can be sandwiched between the inner peripheral surface of the cylindrical member and the outer surface of the columnar body.

[0033] However, the configurations of the columnar body, the buffer member, and the cylindrical member are not limited to the above, and those having a suitable configuration (for example, material and shape, etc.) according to the use environment and use conditions, etc. in the application of the assembly composed of these are selected.

[0034] The first device further includes a contact jig. The contact jig is a member having a contact surface that faces the lower end surface of the buffer member in the vertical direction within the region between the inner peripheral surface of the cylindrical member and the outer surface of the columnar body in the vertical projection onto the horizontal plane. In other words, the contact jig is configured such that the contact surface faces upward with respect to the lower end surface of the buffer member in the space between the inner peripheral surface of the cylindrical member and a virtual inner peripheral surface which is a virtual surface formed by extending the inner peripheral surface downward, and the outer surface of the columnar body.

[0035] The material constituting the contact jig is not particularly limited as long as it can withstand the stress acting on the contact surface that contacts the lower end surface of the buffer member that moves downward with press-fitting. Also, the shape of the contact surface is not particularly limited as long as it can prevent or reduce the downward movement of the buffer member by the contact between the lower end surface of the buffer member and the contact surface of the contact jig. From the viewpoint of reducing problems such as deformation of the buffer member due to the contact between the lower end surface of the buffer member and the contact surface of the contact jig, it is desirable that when the lower end surface of the buffer member and the contact surface of the contact jig come into contact, they contact each other in as large an area as possible. Typically, the contact surface is an annular flat surface corresponding to the shape of the lower end surface of the buffer member.

[0036] Incidentally, as shown in FIG. 16, in the press-fitting device (hereinafter sometimes referred to as "conventional device 1") described in Patent Document 1 mentioned above, a columnar catalyst carrier 200 with a buffer mat 300 wound around its outer surface is placed on a support jig 700. Two-stage annular stepped portions 700a and 700b are formed on the inner surface of the support jig 700. The annular stepped portion 700a is set to be slightly larger in diameter than the outer diameter of the catalyst carrier 200, and the annular stepped portion 700b is larger in diameter than this and is set to be slightly larger in diameter than the outer diameter of the buffer mat 300 before press-fitting. That is, when a columnar catalyst carrier 200 with a buffer mat 300 wound around its outer surface is inserted from above the support jig 700, the catalyst carrier 200 fits into the annular stepped portion 700a, and the buffer mat 300 is configured to fit into the annular stepped portion 700b.

[0037] As described above, in the conventional device 1, in the space between the inner peripheral surface of the cylindrical member 400 and the virtual inner peripheral surface, which is a virtual surface formed by extending the inner peripheral surface downward, and the outer surface of the columnar body (catalyst carrier 200), the lower end surface of the buffer mat 300 and the annular stepped portion 700b face each other in the vertical direction. In this regard, it can be said that the annular stepped portion 700b in the conventional device 1 corresponds to the contact surface in the first device. Also, the guide jig 600 in the conventional device 1 can be said to correspond to the second support portion in the first device.

[0038] However, in the conventional apparatus 1, before the entire buffer member 300 is press-fitted into the cylindrical member 400 when the frictional force acting between the buffer member 300 and the cylindrical member 400 (see the portion β surrounded by the broken line in Fig. 17(a)) reaches its maximum during the press-fitting process, the guiding jig 600 contacts the supporting jig 700 and the supporting jig 700 retracts downward. As a result, the annular step portion 700b is separated from the lower end surface of the buffer mat 300, so that it may not be possible to prevent the buffer member 300 from moving downward with respect to the column body (catalyst carrier 200) during press-fitting.

[0039] Therefore, in the first apparatus, the contact jig is configured so as not to interfere with either the cylindrical member or the second support portion at least during the period from the start to the end of press-fitting. Accordingly, as described above, the cylindrical member and / or the second support portion do not contact the contact jig and the contact surface does not move downward at a point during the press-fitting process.

[0040] Furthermore, in the first apparatus, the contact jig is disposed such that the contact surface is located at a predetermined position included in the first range. The first range is the range from the first position, which is the position in the vertical direction of the lower end surface of the buffer member before press-fitting, to the second position, which is the position in the vertical direction of the lower end surface of the column body. Therefore, when the buffer member moves downward with respect to the column body during press-fitting, the lower end surface of the buffer member can contact the contact surface.

[0041] Note that, as will be described in detail later, the contact surface may be fixed at a predetermined position included in the first range. In this case, the position of the contact surface in the vertical direction can be determined such that the column body, the buffer member, and the cylindrical member are in the desired positional relationship. Alternatively, the contact surface may be movable forward and backward in the vertical direction over a predetermined range included in the first range. In this case, the contact surface is not located below the second position, which is the lower limit of the first range, and the position of the contact surface in the vertical direction when the contact surface is located at the lowest position can be determined such that the column body, the buffer member, and the cylindrical member are in the desired positional relationship.

[0042] FIG. 1 is a schematic diagram showing an example of the configuration of the first device, and (a) and (b) are a front view and a right side view, respectively. The first device 101 illustrated in FIG. 1 is a press-fitting device including a first support portion 110, a second support portion 120, and a press-fitting portion 130. The configuration of the first device 101 will be described in detail below. However, the configuration described in the following description and the corresponding drawings is merely an example of the configuration of the first device, and the configuration of the first device is not limited thereto.

[0043] The first support portion 110 includes a support base 111, a support base 112, and a support column 113. The support base 111 is a pedestal-shaped member having a top surface corresponding to the lower end surface of the column body 200. The column body 200 is placed on the top surface in a posture such that the axial direction of the column body 200 is parallel to the vertical direction. That is, the support base 111 supports the column body 200 from below in a posture such that the axial direction of the column body 200 is parallel to the vertical direction. The support base 111 is supported from below by the support base 112, and the support base 112 is supported from below by the support column 113. Incidentally, a buffer member 300 is wound around the outer surface of the column body 200.

[0044] In the example shown in FIG. 1, the second support portion 120 is slidably supported by a pair of guide rails LM (so-called LM guides) erected so as to be parallel to the vertical line VL and is urged upward by an air cylinder CL fixed to the guide rails LM and is floatingly supported.

[0045] The second support portion 120 supports the cylindrical member 400 in a posture coaxial with the column body 200 above the column body 200 supported by the first support portion 110. In the example shown in FIG. 1, the second support portion 120 has the same configuration as the guide jig 600 provided in the press-fitting device (conventional device 1) described in Patent Document 1 mentioned above. That is, the second support portion 120 has an annular shape and has a tapered portion whose cross-sectional area of the hollow portion gradually increases downward. The cylindrical member 400 is placed on the second support portion 120, and in this state, the hollow portion of the second support portion 120 and the hollow portion of the cylindrical member 400 communicate with each other.

[0046] The press-fitting part 130 drives the column body 200 supported by the first support part 110 and the cylindrical member 400 supported by the second support part 120 to approach each other in the vertical direction, and executes press-fitting of the combination of the column body 200 and the buffer member 300 into the cylindrical member 400. The press-fitting part 130 illustrated in FIG. 1 includes a pressing member 131, a pressing column 132, and an actuator 133.

[0047] The pressing member 131 is connected to the tip of a pressing column 132 driven by an actuator 133 fixed above the guide rail LM, and is supported so as to be able to move forward and backward in the vertical direction on the guide rail LM. The lower end surface of the pressing member 131 is formed into a shape that can be fitted into the upper end opening of the cylindrical member 400. By the operation of the actuator 133, the column body 200 can be pressed downward, and the combination of the column body 200 and the buffer member 300 can be press-fitted into the cylindrical member 400.

[0048] The first device 101 further includes a contact jig 140. The contact jig 140 is a member having a contact surface that is an annular plane facing the lower end surface of the buffer member 300 in the vertical direction within the region between the inner peripheral surface of the cylindrical member 400 and the outer side surface of the column body 200 in the vertical projection onto the horizontal plane. Also, the contact jig 140 is configured so as not to interfere with either the cylindrical member 400 or the second support part 120 at least during the period from the start to the end of the press-fitting. Therefore, unlike the conventional device 1 described above, the cylindrical member 400 and / or the second support part 120 do not contact the contact jig 140 and the contact surface does not move downward at a point during the press-fitting process.

[0049] Furthermore, the contact jig 140 is disposed such that the contact surface is located at a predetermined position included in the first range. The first range is the range from the first position, which is the position in the vertical direction of the lower end surface of the buffer member 300 before the press-fitting is performed, to the second position, which is the position in the vertical direction of the lower end surface of the column body 200. Thereby, as described above, even when the buffer member 300 moves downward with respect to the column body 200 due to the press-fitting, the contact surface contacts the lower end surface of the buffer member 300, and the downward movement of the buffer member can be blocked or reduced.

[0050] FIG. 2 is a schematic cross-sectional view showing an example of the press-fitting process executed using the first device 101. More specifically, FIG. 2 is a schematic view of a portion including a first support portion, a second support portion, and an abutting jig of the first device loaded with a columnar body provided with a buffer member and a cylindrical member, and is a cross-sectional view taken along a plane including the axis AX of the columnar body. In FIG. 2, only the columnar body 200, the buffer member 300, the cylindrical member 400, the first support portion 110, the second support portion 120, and the abutting jig 140 are drawn for the purpose of facilitating the understanding of the press-fitting process, and the press-fitting portion 130 and other members are omitted.

[0051] First, FIG. 2(a) shows a state where the columnar body 200 with the buffer member 300 wound around its outer surface is supported by the first support portion 110 and the cylindrical member 400 is supported by the second support portion 120, but the press-fitting has not yet started. In this example, the buffer member 300 is wound around the outer surface of the columnar body 200 at a predetermined position. And the first device 101 shown in this example is configured such that the abutting surface 140a of the abutting jig 140 and the lower end surface of the buffer member 300 abut when the assembly of the columnar body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110. That is, in this example, the abutting jig 140 is disposed such that the abutting surface 140a is located at a first position which is the position in the vertical direction of the lower end surface of the buffer member 300 before the press-fitting is executed. Therefore, the position of the abutting surface 140a is included in the first range described above.

[0052] On the other hand, FIG. 2(b) shows a state where the press-fitting of the assembly of the columnar body 200 and the buffer member 300 into the cylindrical member 400 is completed by driving the columnar body 200 and the cylindrical member 400 to approach each other in the vertical direction by a press-fitting portion (not shown) (see the black arrow). As described above with reference to FIG. 2(a), the first device 101 is configured such that the abutting surface 140a of the abutting jig 140 and the lower end surface of the buffer member 300 abut when the assembly of the columnar body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110.

[0053] Therefore, for example, when the friction coefficient (static friction coefficient and / or dynamic friction coefficient) between the columnar body 200 and the buffer member 300 is lower than the friction coefficient between the buffer member 300 and the cylindrical member 400, even when there is a high possibility that the buffer member 300 moves downward with respect to the columnar body 200 during press-fitting, the contact between the lower end surface of the buffer member 300 and the contact surface 140a can surely prevent or reduce the downward movement of the lower end surface of the buffer member 300.

[0054] By the way, in the example shown in FIG. 2, as described above, the buffer member 300 was wound around the expected position on the outer surface of the columnar body 200. However, in anticipation of the buffer member 300 moving downward with respect to the columnar body 200 during press-fitting, the buffer member 300 may be wound around a position that is a predetermined length above the expected position on the outer surface of the columnar body 200. FIG. 3(a) shows, as in FIG. 2(a) described above, a state in which the columnar body 200 with the buffer member 300 wound around its outer surface is supported by the first support portion 110 and the cylindrical member 400 is supported by the second support portion 120, but the press-fitting has not yet started. However, in this example, the buffer member 300 is wound around a position that is a predetermined length above the expected position on the outer surface of the columnar body 200.

[0055] And in the first device 101 shown in this example, when the set of the columnar body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110, the contact surface 140a of the contact jig 140 and the lower end surface of the buffer member 300 are not in contact. More specifically, the contact surface 140a is arranged to be separated from the lower end surface of the buffer member 300 at a position that is below the lower end surface of the buffer member 300 and above the lower end surface of the columnar body 200. That is, also in this example, the position of the contact surface 140a is included in the first range described above.

[0056] On the one hand, (b) of FIG. 3 shows a state where the column body 200 and the cylindrical member 400 are driven by a press-fitting portion (not shown) so as to approach each other in the vertical direction (see the black arrow), and the press-fitting of the combination of the column body 200 and the buffer member 300 into the cylindrical member 400 is completed. As described above with reference to (a) of FIG. 3, in this example, anticipating that the buffer member 300 will move downward with respect to the column body 200 during press-fitting, the buffer member 300 is wound around a position above the intended position on the outer surface of the column body 200 by a predetermined length. In a state where the combination of the column body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110, the contact surface 140a of the contact jig 140 and the lower end surface of the buffer member 300 are not in contact.

[0057] Incidentally, as described above, for example, when the friction coefficient (static friction coefficient and / or kinetic friction coefficient) between the column body 200 and the buffer member 300 is lower than the friction coefficient between the buffer member 300 and the cylindrical member 400, there is a possibility that the buffer member 300 may start to move downward with respect to the column body 200 during press-fitting. Even if the buffer member 300 starts to move downward with respect to the column body 200 in this way during press-fitting, for example, due to the surface properties of the outer surface of the column body 200, the bulk density of the buffer member 300, the surface properties of the inner peripheral surface of the cylindrical member 400, and the change in the vertical direction of the interval between the outer surface of the column body 200 and the inner peripheral surface of the cylindrical member 400, the downward movement of the buffer member 300 may stop before the lower end surface of the buffer member 300 reaches the contact surface 140a. However, generally, the kinetic friction coefficient is smaller than the static friction coefficient. Therefore, once the buffer member 300 starts to move downward during press-fitting, the possibility that the downward movement of the buffer member 300 stops before the lower end surface of the buffer member 300 reaches the contact surface 140a is low.

[0058] That is, after the buffer member 300 starts to move downward once with the press-fitting, the buffer member 300 often continues to move downward until at least the lower end surface of the buffer member 300 reaches the contact surface 140a. Even in such a case, in the first device 101 illustrated in FIG. 3, when the lower end surface of the buffer member 300 and the contact surface 140a eventually come into contact, it is possible to surely prevent or reduce the further downward movement of the lower end surface of the buffer member 300.

[0059] In addition, as described above with reference to FIGS. 2 and 3, as a result of the downward movement of the buffer member 300 accompanying the press-fitting being blocked or reduced by the contact between the lower end surface of the buffer member 300 and the contact surface 140a, deformation of the buffer member 300 may occur. The degree of deformation of the buffer member 300 varies depending on, for example, the relationship between the magnitude of the force acting downward on the buffer member 300 with the press-fitting, the rigidity and / or elastic modulus of the buffer member 300. For example, the smaller the rigidity and / or elastic modulus of the buffer member 300 with respect to the magnitude of the force acting downward on the buffer member 300 with the press-fitting, the greater the shrinkage rate of the buffer member 300 in the vertical direction with the press-fitting. Conversely, the greater the rigidity and / or elastic modulus of the buffer member 300 with respect to the magnitude of the force acting downward on the buffer member 300 with the press-fitting, the smaller the shrinkage rate of the buffer member 300 in the vertical direction with the press-fitting.

[0060] Also, the shrinkage rate of the buffer member 300 in the vertical direction with the press-fitting also varies depending on the length of the period during which the lower end surface of the buffer member 300 presses the contact surface 140a and the magnitude of the force received by the lower end surface of the buffer member 300 from the contact surface 140a during that period. For example, when the buffer member moves downward with respect to the column body with the press-fitting, the shrinkage rate of the buffer member 300 in the situation where the lower end surface of the buffer member 300 and the contact surface 140a are in contact throughout the entire period from the start to the end of the press-fitting as shown in FIG. 2 is greater than the shrinkage rate of the buffer member 300 in the situation where the lower end surface of the buffer member 300 and the contact surface 140a are in contact only during a part (the latter half) of the period from the start to the end of the press-fitting as shown in FIG. 3.

[0061] Incidentally, in FIGS. 2 and 3 and the above description, the case where the contact surface is fixed at a predetermined position included in the first range has been described. However, as described above, the contact surface may be movable back and forth in the vertical direction over a predetermined range included in the first range. In any case, the position of the contact surface in the vertical direction when the contact surface is located at the lowest position can be determined so that the column body, the buffer member, and the cylindrical member are in the desired positional relationship.

[0062] <Effect> As described above, in the first device, even when the buffer member moves downward with respect to the column body due to press-fitting, the downward movement of the buffer member can be blocked or reduced by the contact between the lower end surface of the buffer member and the contact surface of the contact jig. As a result, it is possible to surely prevent the lower end surface of the buffer member from moving downward beyond the desired position included in the first range. That is, according to the first device, when press-fitting a column body having a buffer member disposed on its outer surface into the inside of a cylindrical member, regardless of the magnitude relationship of the friction coefficients between the column body, the buffer member, and the cylindrical member, these can be surely mounted so as to be in the desired positional relationship, and the column body can be held at a predetermined position inside the cylindrical member.

[0063] <<Second Embodiment>> Hereinafter, a press-fitting device (hereinafter, may be referred to as the "second device") according to the second embodiment of the present invention will be described with reference to the drawings. As described in the description regarding the first device, the contact surface may be fixed at a predetermined position included in the first range.

[0064] <Configuration> Therefore, the second device is the above-described first device, and is characterized in that a contact jig is disposed such that the contact surface is fixed at a third position which is a predetermined position included in the first range.

[0065] As described above, in the description of the first device with reference to FIGS. 2 and 3 and the corresponding description of these figures, the case where the contact surface is fixed at a predetermined position included in the first range has been described. That is, the first device 101 illustrated in FIGS. 2 and 3 also corresponds to the second device. In FIGS. 2(a) and 3(a), the first position, which is the position in the vertical direction of the lower end surface of the buffer member 300 before press-fitting, is indicated by the dashed arrow P1, and the second position, which is the position in the vertical direction of the lower end surface of the column body 200, is indicated by the dashed arrow P2. Therefore, the range from the first position P1 to the second position P2 is the first range.

[0066] In the example shown in FIG. 2, as described above, the buffer member 300 is wound around the outer surface of the column body 200 at a predetermined position. And in a state where the assembly of the column body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110, the contact surface 140a of the contact jig 140 is in contact with the lower end surface of the buffer member 300. That is, in this example, the contact jig 140 is fixed so that the contact surface 140a is located at the first position, which is the position in the vertical direction of the lower end surface of the buffer member 300 before press-fitting. Therefore, in this example, the third position P3 coincides with the first position P1.

[0067] On the other hand, in the example shown in FIG. 3, as described above, anticipating that the buffer member 300 moves downward with respect to the column body 200 along with press-fitting, the buffer member 300 is wound around a position a predetermined length above a predetermined position on the outer surface of the column body 200. And in a state where the assembly of the column body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110, the contact surface 140a of the contact jig 140 is fixed at a position separated from the lower end surface of the buffer member 300 at a position below the lower end surface of the buffer member 300 and above the lower end surface of the column body 200. That is, in this example, the third position P3 is a position below the first position P1 and above the second position P2 (see the dashed arrow P3 shown in the figure).

[0068] <Effect> As described above, in the second device, the contact jig is arranged such that the contact surface is fixed at a third position which is a predetermined position included in a first range that is a range from a first position which is the position in the vertical direction of the lower end surface of the buffer member before press-fitting to a second position which is the position in the vertical direction of the lower end surface of the column body. Therefore, it is possible to surely prevent the lower end surface of the buffer member from moving downward from the third position along with the press-fitting. Accordingly, by determining the third position so that the column body, the buffer member, and the cylindrical member have a desired positional relationship in the second device, when press-fitting the column body having the buffer member disposed on its outer surface into the inside of the cylindrical member, regardless of the magnitude relationship of the friction coefficients among the column body, the buffer member, and the cylindrical member, these can be more surely mounted so as to have the desired positional relationship, and the column body can be held at a predetermined position inside the cylindrical member.

[0069] <<Third Embodiment>> Hereinafter, a press-fitting device according to a third embodiment of the present invention (hereinafter, may be referred to as the "third device") will be described with reference to the drawings. As described in the description regarding the first device, the contact surface may be movable back and forth in the vertical direction over a predetermined range included in the first range.

[0070] <Configuration> Therefore, the third device is the above-described first device, and the contact jig is configured such that the contact surface is movable back and forth in the vertical direction over a second range which is a range from the third position to the fourth position, and the contact jig is arranged such that the contact surface is positioned at the third position at the time when press-fitting is started. The third position is a predetermined position included in the first range, and the fourth position is a position included in the first range and positioned below the third position. In other words, the upper limit position of the movable range of the contact surface that is movable back and forth in the vertical direction is the third position, and the lower limit position of the movable range is the fourth position. The configuration for making the contact surface movable back and forth in the vertical direction over the second range is not particularly limited. For example, a portion having the contact surface of the contact jig may be supported by a support column that is slidably fitted or inserted in a hole formed in a support base in the vertical direction.

[0071] Furthermore, the third device further includes a biasing portion that drives the contact jig so that the contact surface is biased upward. The configuration of the biasing portion is not particularly limited as long as it is capable of driving the contact jig so that the contact surface is biased upward. Specific examples of the configuration of the biasing portion include, for example, a mechanism including an elastic member (e.g., an elastic material such as various springs and rubbers) configured to bias the contact surface upward and a mechanism including a pressure drive system (e.g., a hydraulic cylinder) configured to bias the contact surface upward by some air pressure or hydraulic pressure.

[0072] In the third device, with the above configuration, the contact jig is configured such that the contact surface, which is movable back and forth over the second range, is located at the third position when the press-fitting is started.

[0073] In addition, the biasing portion is configured such that the biasing force is smaller than the pressing force during at least a part of the period from the time when the lower end surface of the buffer member comes into contact with the contact surface to the time when the press-fitting ends. Here, the biasing force is the force applied upward to the contact surface by the biasing portion, and the pressing force is the force with which the lower end surface of the buffer member presses the contact surface downward.

[0074] The means for setting the biasing force as described above is not particularly limited. For example, when the biasing portion is configured by a mechanism including an elastic member (e.g., an elastic material such as various springs and rubbers) configured to bias the contact surface upward, the elastic modulus of the elastic member constituting the biasing portion may be changed by replacing the elastic member constituting the biasing portion. Alternatively, the biasing portion may be provided with a mechanism for increasing or decreasing the initial length of the elastic member in the vertical direction. On the other hand, when the biasing portion is configured by a mechanism including the above-described pressure drive system, the pressure drive system may be provided with a mechanism for increasing or decreasing the pressure of the fluid (gas or liquid) that exerts the driving force for driving the contact jig by the pressure drive system.

[0075] FIG. 4 is a drawing corresponding to FIG. 3 referred to in the description of the above-described first device and second device, and is a schematic cross-sectional view taken along a plane including the axis AX of the column body on which the buffer member is disposed and the column body of the portion including the first support portion, the second support portion, and the abutting jig of the third device loaded with the cylindrical member. Also in FIG. 4, similar to FIG. 3, for the purpose of facilitating the understanding of the press-fitting process, only the column body 200, the buffer member 300, the cylindrical member 400, the first support portion 110, the second support portion 120, and the abutting jig 140 are depicted, and the press-fitting portion 130 and other members are omitted.

[0076] As shown in FIG. 4(a), similar to FIG. 3(a), the column body 200 with the buffer member 300 wound around its outer surface is supported by the first support portion 110, and the cylindrical member 400 is supported by the second support portion 120, but the press-fitting has not yet started. Also, anticipating that the buffer member 300 will move downward with respect to the column body 200 during press-fitting, the buffer member 300 is wound at a position a predetermined length above the intended position on the outer surface of the column body 200.

[0077] Furthermore, the first position, which is the position in the vertical direction of the lower end surface of the buffer member 300 before press-fitting, is indicated by the dashed arrow P1, and the second position, which is the position in the vertical direction of the lower end surface of the column body 200, is indicated by the dashed arrow P2. Therefore, the range from the first position P1 to the second position P2 is the first range. And in the state where the assembly of the column body 200 and the buffer member 300 is placed on the support base 111 provided in the first support portion 110, the abutting surface 140a of the abutting jig 140 and the lower end surface of the buffer member 300 are not in contact. More specifically, the abutting surface 140a is arranged to be separated from the lower end surface of the buffer member 300 at a position below the lower end surface (first position P1) of the buffer member 300 and above the lower end surface (second position P2) of the column body 200. That is, at the time when press-fitting is started, the abutting surface 140a is at a predetermined position included in the first range, and this position corresponds to the third position P3.

[0078] However, as described above, in the third device 103, the contact jig 140 is configured such that the contact surface is movable forward and backward in the vertical direction over a second range that is included in the first range and is located below the third position P3 to a fourth position (see the dashed arrow P4 shown in FIG. 4(b)) from the third position P3. More specifically, the contact jig 140 included in the third device 103 includes a contact portion 141, a support column 142, a stopper 143, and a biasing portion 144.

[0079] The contact portion 141 is a member having the contact surface 140a of the contact jig 140. The support column 142 is a member that is slidably inserted into a through-hole formed vertically in the support base 112 that constitutes the first support portion 110 and supports the contact portion 141 from below. The stopper 143 is a member configured to prevent the contact surface 140a from moving upward beyond the third position P3 by contacting the lower end surface of the support base 112. The biasing portion 144 is a mechanism including a spring as an elastic member that biases the contact portion 141 upward. The contact portion 141 is configured such that when its lower end surface contacts the upper end surface of the support base 112, the contact surface 140a is prevented from moving downward beyond the fourth position P4. From such a perspective, it can be said that the lower end surface of the contact portion 141 is a stopper configured to prevent the contact surface 140a from moving downward beyond the fourth position P4.

[0080] In the third device 103, with the above configuration, the contact surface 140a is movable forward and backward in the vertical direction over the second range that is the range from the third position P3 to the fourth position P4, and the contact jig 140 is configured such that the contact surface 140a is located at the third position P3 at the time when press-fitting is started.

[0081] On the other hand, (b) of FIG. 4 shows a state where the column body 200 and the cylindrical member 400 are driven by a press-fitting portion (not shown) so as to approach each other in the vertical direction (see the black arrow), and the press-fitting of the combination of the column body 200 and the buffer member 300 into the cylindrical member 400 is completed. As described above, for example, when the friction coefficient (static friction coefficient and / or kinetic friction coefficient) between the column body 200 and the buffer member 300 is lower than the friction coefficient between the buffer member 300 and the cylindrical member 400, and the buffer member 300 moves downward with respect to the column body 200 during press-fitting, generally, the lower end surface of the buffer member 300 eventually comes into contact with the contact surface 140a located at the third position P3.

[0082] After the lower end surface of the buffer member 300 comes into contact with the contact surface 140a, the contact surface 140a is pressed by the lower end surface of the buffer member 300, and the contact jig 140 moves downward while compressing the spring provided in the biasing portion 144 (see the thin solid-line arrow shown in (b) of FIG. 4). Eventually, the downward movement of the contact jig 140 stops when the lower end surface of the contact portion 141 comes into contact with the upper end surface of the support base 112, and the contact surface 140a is fixed at the fourth position P4. Then, when the contact surface 140a is fixed at the fourth position P4 as described above or at a predetermined time point after that time point, the cylindrical member 400 descends to a desired position, and the press-fitting is completed.

[0083] By the way, the magnitude of the downward movement distance of the buffer member 300 after the buffer member 300 moves downward with respect to the column body 200 during press-fitting and the lower end surface of the buffer member 300 comes into contact with the contact surface 140a as described above is determined by the relationship between the magnitude of the biasing force, which is the force applied upward to the contact surface 140a by the biasing portion 144, and the magnitude of the pressing force, which is the force with which the lower end surface of the buffer member 300 presses the contact surface 140a downward.

[0084] For example, when the biasing force is greater than the pressing force throughout the period from the time when the lower end surface of the buffer member 300 contacts the contact surface 140a to the time when the press-fitting ends, even after the lower end surface of the buffer member 300 contacts the contact surface 140a at the third position P3, the contact surface 140a remains at the third position P3, and the downward movement of the lower end surface of the buffer member 300 is prevented. That is, in this case, since the contact surface 140a is substantially fixed at the third position P3, the press-fitting device corresponds to the second device described above.

[0085] However, in the third device 103, as described above, the biasing force is configured to be smaller than the pressing force during at least a part of the period from the time when the lower end surface of the buffer member 300 contacts the contact surface 140a to the time when the press-fitting ends. Although the specific configuration of the means for setting the biasing force is not depicted in FIG. 4 and has already been described above, the description here is omitted.

[0086] With the above configuration, in the third device 103, during at least a part of the period from the time when the lower end surface of the buffer member 300 contacts the contact surface 140a to the time when the press-fitting ends, the contact surface 140a is pressed downward by the lower end surface of the buffer member 300, and the contact jig 140 moves downward. However, as described above, since the downward movement of the contact surface 140a is prevented by the contact between the lower end surface of the contact portion 141 and the upper end surface of the support base 112, the lower end surface of the buffer member 300 does not move downward from the fourth position P4.

[0087] <Effect> As described above, in the third device, the contact jig is configured such that the contact surface is movable back and forth in the vertical direction over a second range that is a range from a third position, which is a predetermined position included in the first range, to a fourth position that is included in the first range and is located below the third position. Further, the contact jig is disposed such that the contact surface is located at the third position when press-fitting is started. Furthermore, the third device further includes a biasing unit that drives the contact jig so that the contact surface is biased upward. In addition, the biasing unit is configured such that the biasing force is smaller than the pressing force at least during a part of the period from the time when the lower end surface of the buffer member comes into contact with the contact surface to the time when press-fitting ends.

[0088] With the above configuration, in the third device, during at least a part of the period from the time when the lower end surface of the buffer member comes into contact with the contact surface to the time when press-fitting ends, the contact surface is pressed downward by the lower end surface of the buffer member and the contact jig moves downward. However, as described above, the contact surface does not move below the fourth position, and the lower end surface of the buffer member also does not move below the fourth position. Therefore, it is possible to reliably prevent the lower end surface of the buffer member from moving below the fourth position along with press-fitting. Accordingly, by determining the fourth position so that the column body, the buffer member, and the cylindrical member have the intended positional relationship in the third device, when press-fitting a column body having a buffer member disposed on its outer surface into the inside of the cylindrical member, regardless of the magnitude relationship of the friction coefficients among the column body, the buffer member, and the cylindrical member, these can be more reliably mounted so as to have the intended positional relationship, and the column body can be held at a predetermined position inside the cylindrical member.

[0089] Further, the degree of deformation of the buffer member that may result from the downward movement of the buffer member due to press-fitting being blocked or reduced by the contact between the lower end surface of the buffer member and the contact surface, as described above, varies depending on the temporal length of the period during which the lower end surface of the buffer member presses the contact surface in the press-fitting process and the magnitude of the force received by the lower end surface of the buffer member from the contact surface during that period. In the first device 101 corresponding to the second device illustrated in FIG. 3 and the third device 103 illustrated in FIG. 4, the temporal length of the period during which the lower end surface of the buffer member 300 presses the contact surface 140a in the press-fitting process is the same.

[0090] However, the biasing portion 144 provided in the third device 103 is configured such that the biasing force is smaller than the pressing force at least during a part of the period from the time when the lower end surface of the buffer member 300 comes into contact with the contact surface 140a to the time when the press-fitting ends. Therefore, in the third device 103, the force received by the lower end surface of the buffer member 300 from the contact surface 140a is smaller than that in the first device 101 corresponding to the second device at least during a part of the period during which the contact surface 140a pressed by the lower end surface of the buffer member 300 descends from the third position P3 to the fourth position P4. Therefore, the degree of deformation (the shrinkage rate in the vertical direction of the buffer member 300) of the buffer member 300 that may result from the downward movement of the buffer member 300 due to press-fitting being blocked or reduced by the contact between the lower end surface of the buffer member 300 and the contact surface 140a is smaller in the third device 103 than in the first device 101 corresponding to the second device.

[0091] As described above, in the third device, the shrinkage rate in the vertical direction of the buffer member due to press-fitting can be reduced. Therefore, according to the third device, even when an assembly in which a columnar body having a buffer member disposed on its outer surface is press-fitted into a cylindrical member is used in applications where an increase in the bulk density of the buffer member due to press-fitting is not desirable, etc., regardless of the magnitude relationship of the friction coefficients between the columnar body, the buffer member, and the cylindrical member, these can be more reliably mounted in the desired positional relationship to manufacture the assembly.

[0092] <<Fourth Embodiment>> Hereinafter, a press-fitting device according to a fourth embodiment of the present invention (hereinafter may be referred to as the "fourth device") will be described with reference to the drawings.

[0093] As described above, the third device is configured such that the contact surface is vertically movable back and forth over a predetermined range included in the first range, and the biasing force is smaller than the pressing force at least during a part of the period from the time when the lower end surface of the buffer member contacts the contact surface to the time when the press-fitting ends. As a result, according to the third device, while reducing the shrinkage rate in the vertical direction of the buffer member accompanying the press-fitting, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be more reliably mounted so as to have the intended positional relationship, and the columnar body can be held at a predetermined position inside the cylindrical member.

[0094] However, depending on the use of the assembly in which the columnar body with the buffer member disposed on the outer surface is press-fitted into the cylindrical member, it may be desirable to adjust the bulk density of the buffer member (particularly near the lower end surface) so as to reach the desired value as the press-fitting process progresses.

[0095] <Configuration> Therefore, the fourth device is the first device described above, and the contact jig is configured such that the contact surface is vertically movable back and forth over a second range that is a range from the third position to the fourth position, and the contact jig is disposed such that the contact surface is located at the third position at the time when the press-fitting is started. The third position is a predetermined position included in the first range, and the fourth position is a position included in the first range and located below the third position. As described above, the upper limit position of the movable range of the contact surface that is vertically movable back and forth is the third position, and the lower limit position of the movable range is the fourth position. The configuration for making the contact surface vertically movable back and forth over the second range is not particularly limited. For example, a portion having the contact surface of the contact jig may be supported by a support column that is slidably fitted or inserted vertically into a hole formed in the support base.

[0096] In addition, the fourth device further includes a drive unit that drives the contact jig so that the contact surface moves at a predetermined speed over the second range. The configuration of the drive unit is not particularly limited as long as it can drive the contact jig so that the contact surface moves at a predetermined speed over the second range. Specific examples of the configuration of the drive unit include, for example, a mechanism including a pressure drive system (e.g., a hydraulic cylinder, etc.) configured to bias the contact surface upward by some air pressure or hydraulic pressure, and a mechanism including an electric motor (motor) that operates by energization, etc.

[0097] In the fourth device, since the position of the contact surface can be controlled by the drive unit, the third position, which is the upper limit position of the second range, and the fourth position, which is the lower limit position of the second range, which are the movable ranges of the contact surface that can move forward and backward in the vertical direction, can be determined by the drive unit. However, in the fourth device, the upper limit position and / or the lower limit position of the second range may be determined as the third position and / or the fourth position, respectively, by a mechanism including members such as the stopper provided in the third device and the lower end surface of the contact portion. Further, the fourth device may further include a biasing unit provided in the third device.

[0098] FIG. 5 is a drawing corresponding to FIG. 3 referred to in the description regarding the first device and the second device described above, and is a schematic cross-sectional view taken along a plane including the axis AX of the column body including the buffer member and the column body portion including the first support portion, the second support portion, and the contact jig of the fourth device loaded with the cylindrical member. In FIG. 5, for the purpose of facilitating the understanding of the press-fitting process, only the column body 200, the buffer member 300, the cylindrical member 400, the first support portion 110, the second support portion 120, the contact jig 140, and the drive unit 150 are depicted, and the press-fitting portion 130 and other members are omitted.

[0099] As shown in Fig. 5(a), similar to Fig. 3(a), the column body 200 with the buffer member 300 wound around its outer surface is supported by the first support portion 110, and the cylindrical member 400 is supported by the second support portion 120, but the press-fitting has not yet started. Also, in anticipation of the buffer member 300 moving downward relative to the column body 200 with the press-fitting, the buffer member 300 is wound around a position that is a predetermined length above the intended position on the outer surface of the column body 200.

[0100] Furthermore, the first position, which is the position in the vertical direction of the lower end surface of the buffer member 300 before the press-fitting is executed, is indicated by the dashed arrow P1, and the second position, which is the position in the vertical direction of the lower end surface of the column body 200, is indicated by the dashed arrow P2. Therefore, the range from the first position P1 to the second position P2 is the first range. At the time when the press-fitting starts, the contact surface 140a is arranged to be separated from the lower end surface of the buffer member 300 at a position that is below the lower end surface (the first position P1) of the buffer member 300 and above the lower end surface (the second position P2) of the column body 200. That is, the contact surface 140a is at a predetermined position included in the first range, and this position corresponds to the third position P3.

[0101] The contact jig 140 provided in the fourth device 104 includes a contact portion 141 and a support column 142. The contact portion 141 is a member having the contact surface 140a of the contact jig 140, and the support column 142 is a member that is slidably inserted into a through hole formed vertically in the support base 112 constituting the first support portion 110 and supports the contact portion 141 from below.

[0102] The fourth device 104 further includes a driving unit 150. The driving unit 150 illustrated in FIG. 5 is a mechanism including a stepping motor as an actuator that drives the support column 142 provided in the contact jig 140 in the vertical direction. In the fourth device 104, the position of the contact surface can be precisely controlled by the driving unit 150. Therefore, the driving unit 150 can drive the contact jig so that the contact surface 140a moves at a predetermined speed over the second range. Also, the third position P3, which is the upper limit position of the second range that is the movable range of the contact surface that can move forward and backward in the vertical direction, and the fourth position P4, which is the lower limit position, can be appropriately determined by setting the range for driving the support column 142 by the driving unit. Further, by the driving unit 150, the contact jig 140 can be driven so that the contact surface 140a is positioned at the third position P3 at the time when press-fitting is started.

[0103] On the other hand, FIG. 5(b) shows a state in which the column body 200 and the cylindrical member 400 are driven by a press-fitting part (not shown) so as to approach each other in the vertical direction (see the black arrow), and the press-fitting of the set of the column body 200 and the buffer member 300 into the cylindrical member 400 is completed. As described above, for example, when the friction coefficient (static friction coefficient and / or dynamic friction coefficient) between the column body 200 and the buffer member 300 is lower than the friction coefficient between the buffer member 300 and the cylindrical member 400, and the buffer member 300 moves downward with respect to the column body 200 during press-fitting, generally, the lower end surface of the buffer member 300 will eventually contact the contact surface 140a positioned at the third position P3.

[0104] After the lower end surface of the buffer member 300 contacts the contact surface 140a, the contact surface 140a is pressed by the lower end surface of the buffer member 300. Eventually, when the contact surface 140a descends from the third position P3 to the fourth position P4, the driving (movement) of the contact jig 140 by the driving unit 150 stops, and the contact surface 140a is fixed at the fourth position P4. Then, at the time when the contact surface 140a is fixed at the fourth position P4 as described above or at a predetermined time after that time, the cylindrical member 400 descends to the expected position, and the press-fitting is completed.

[0105] In the press-fitting process as described above, the magnitude of the force received by the lower end surface of the buffer member 300 from the contact surface 140a varies depending on the difference in the descending speed of the cylindrical member 400 driven by the press-fitting portion 130 and the descending speed of the contact jig 140 (contact surface 140a thereof) driven by the driving portion 150. Specifically, the lower the descending speed of the contact surface 140a relative to the descending speed of the cylindrical member 400 (the slower it is), the greater the force received by the lower end surface of the buffer member 300 from the contact surface 140a, the greater the shrinkage rate of the buffer member 300 in the vertical direction, and the greater the bulk density of the buffer member 300 (especially in the vicinity of the lower end surface).

[0106] Therefore, by controlling the descending speed of the contact jig 140 (contact surface 140a thereof) by the driving portion 150, it is possible to control the magnitude of the change (increase) in the bulk density of the buffer member 300 (especially in the vicinity of the lower end surface) during the press-fitting process, and make the bulk density of the buffer member 300 at the completion of press-fitting a desired value.

[0107] <Effect> As described above, in the fourth device, by controlling the moving speed of the contact surface in the second range described above by the driving portion, the shrinkage rate of the buffer member in the vertical direction accompanying press-fitting is controlled, and the bulk density of the buffer member (especially in the vicinity of the lower end surface) at the completion of press-fitting can be easily made a desired value.

[0108] Furthermore, as described above, by appropriately setting the range in which the support column is driven by the driving portion, the third position which is the upper limit position of the second range and the fourth position which is the lower limit position, which are the movable ranges of the contact surface that can move forward and backward in the vertical direction, can be changed. Therefore, for example, when any one of the column body, the buffer member, and the cylindrical member constituting the integrated body integrated by press-fitting using the fourth device is changed due to a brand change or the like, the third position and the fourth position can be easily changed by setting of the driving portion. As a result, for example, the labor, time, and cost required for changing the manufacturing conditions accompanying a brand change or the like can be reduced.

[0109] <<Fifth Embodiment>> Hereinafter, a press-fitting device according to a fifth embodiment of the present invention (hereinafter, may be referred to as the "fifth device") will be described with reference to the drawings.

[0110] Incidentally, as described above, specific examples of the columnar body include, for example, a catalyst carrier constituting a catalytic converter and a ceramic honeycomb structure as a heating element constituting an electric heating catalyst (EHC). The lower end surface of such a columnar body should originally be a plane orthogonal to the axis of the columnar body. However, in actuality, the lower end surface of the columnar body may not be perpendicular to the axis of the columnar body. In this case, when the columnar body is placed on the support table having the first support portion in a posture where the axial direction is parallel to the vertical direction, there is a risk that the lower end surface of the columnar body and the support table come into local contact, leading to problems such as breakage of the columnar body due to stress concentration.

[0111] <Configuration> Therefore, the fifth device is any one of the above-described first to fourth devices, and is a press-fitting device characterized in that the support table is configured such that a support surface, which is the top surface of the support table, is tiltable within a predetermined angle range with respect to the horizontal plane.

[0112] As described above, the support surface is the top surface of the support table and is a surface that comes into contact with the lower end surface of the columnar body in a state where the columnar body is supported from below by the first support portion. The configuration for making the support surface tiltable within a predetermined angle range with respect to the horizontal plane is not particularly limited. For example, the support table is divided into a placement portion, which is a member having a top surface (i.e., the support surface) on which the columnar body is placed, and a support portion that supports the placement portion from below, and the placement portion and the support portion are connected by a tiltable connection mechanism such as a spherical bearing, whereby the support surface can be made tiltable with respect to the horizontal plane. Also, for example, the tiltable angle of the support surface can be restricted to a predetermined range by arranging a plurality of members facing the bottom surface of the placement portion at a predetermined interval. Further, for example, the angle of the support surface in a state where no external force acts can be maintained horizontally by arranging a member that biases the placement portion upward from below.

[0113] FIG. 6 is a drawing corresponding to FIG. 3 referred to in the description of the above-described first device and second device, and is a schematic cross-sectional view taken along a plane including the axis AX of the column body provided with the buffer member and the column body of the portion including the first support portion, the second support portion, and the abutting jig of the fifth device loaded with the cylindrical member. Also in FIG. 6, similar to FIG. 3, for the purpose of facilitating the understanding of the press-fitting process, only the column body 200, the buffer member 300, the cylindrical member 400, the first support portion 110, the second support portion 120, and the abutting jig 140 are drawn, and the press-fitting portion 130 and other members are omitted.

[0114] (a) of FIG. 6 represents a state where the press-fitting has not yet started, similar to (a) of FIG. 3. The positional relationship among the column body 200, the buffer member 300, the cylindrical member 400, the first support portion 110, and the second support portion 120 is also the same as that in (a) of FIG. 3, and the first position, the second position, and the third position are indicated by the dashed arrows P1, P2, and P3, respectively. The range from the first position P1 to the second position P2 is the first range.

[0115] The support base 111 constituting the first support portion 110 included in the fifth device 105 is divided into a placement portion 111a and a support portion 111b. At the center of the top surface of the support portion 111b, a spherical portion 111c having an upwardly convex spherical surface is provided. On the other hand, at the center of the bottom surface of the placement portion 111a, a hole having a downwardly concave spherical surface corresponding to the spherical surface of the spherical portion 111c is provided. By slidably fitting the spherical surface of the spherical portion 111c into the hole of the placement portion 111a, the placement portion 111a and the support portion 111b are connected like a spherical bearing. With such a configuration, the support base 111 is configured such that the support surface, which is the top surface of the support base 111 (constituting the placement portion 111a), can tilt with respect to the horizontal plane.

[0116] The fifth device 105 illustrated in FIG. 6 further includes a plurality of tilting restricting portions 114 and a plurality of horizontal maintaining portions 115. The tilting restricting portion 114 is a member that faces the bottom surface of the mounting portion 111a at a predetermined interval. The horizontal maintaining portion 115 is a mechanism including a spring as a member that biases the mounting portion 111a upward from below. In the fifth device 105, the plurality of tilting restricting portions 114 and the plurality of horizontal maintaining portions 115 are alternately and equally spaced around the spherical surface portion 111c. As a result, the tiltable angle of the support surface, which is the top surface of the support base 111 (the mounting portion 111a that constitutes it), is restricted to a predetermined range (for example, ±1° with respect to the horizontal plane), and the support surface is maintained horizontally in a state where no external force acts. However, the tilting restricting portion 114 and the horizontal maintaining portion 115 are not essential components of the fifth device and can be provided as necessary.

[0117] On the other hand, FIG. 6(b) shows a state in which the column body 200 and the cylindrical member 400 are driven by a press-fitting portion (not shown) to approach each other in the vertical direction (see the black arrow), and the press-fitting of the set of the column body 200 and the buffer member 300 into the cylindrical member 400 is completed. According to the fifth device 105 having the configuration as described above, even when the lower end surface of the column body 200 is not horizontal (not perpendicular to the axis of the column body 200), the mounting portion 111a can be inclined so that the lower end surface of the column body 200 and the support surface are in surface contact. Therefore, even during the press-fitting process, it is possible to reduce the risk of problems such as breakage of the column body 200 caused by local contact between the lower end surface of the column body 200 and the support surface and stress concentration.

[0118] <Effect> As described above, in the fifth device, the support base is configured such that the support surface, which is the top surface of the support base, is tiltable within a predetermined angle range with respect to the horizontal plane. Therefore, even when the lower end surface of the column body is not horizontal (not perpendicular to the axis of the column body), the support surface is inclined according to the angle of the lower end surface of the column body, and the lower end surface of the column body and the support surface can be in surface contact. As a result, it is possible to reduce the risk of problems such as breakage of the column body caused by local contact between the lower end surface of the column body and the support surface and stress concentration.

[0119] <<Sixth Embodiment>> Hereinafter, a press-fitting method according to the sixth embodiment of the present invention (hereinafter, may be referred to as the "first method") will be described with reference to the drawings.

[0120] As described at the beginning of this specification, the present invention relates not only to the press-fitting device as described above, but also to a press-fitting method using the press-fitting device according to the present invention.

[0121] <Configuration> As described above, the first method is a press-fitting method of press-fitting a columnar body having a buffer member disposed on its outer surface into the inside of a cylindrical member using a press-fitting device. The press-fitting device used in the first method is the press-fitting device (first device) according to the first embodiment of the present invention described above. Since the configuration and operation of the first device have already been described in detail in the description of the first device, the description here is omitted. Further, the first method includes the first to fourth steps listed below.

[0122] First step: A buffer member is disposed on the outer surface of the columnar body. Second step: The columnar body having the buffer member disposed on its outer surface is supported by the first support portion in a posture in which the axial direction of the columnar body is parallel to the vertical direction. Third step: Above the columnar body supported by the first support portion, the cylindrical member is supported by the second support portion in a posture coaxial with the columnar body. Fourth step: The columnar body supported by the first support portion and the cylindrical member supported by the second support portion are driven by the press-fitting portion so as to approach each other in the vertical direction, and the assembly of the columnar body and the buffer member is press-fitted into the inside of the cylindrical member.

[0123] Furthermore, in the first method, even when the buffer member moves downward with respect to the columnar body during the execution of the press-fitting, the lower end surface of the buffer member is prevented from moving downward from the contact surface by the contact between the lower end surface of the buffer member and the contact surface.

[0124] However, as described in the description of the first device, the contact surface may be fixed at a predetermined position included in the first range, or may be able to move back and forth in the vertical direction over a predetermined range included in the first range. In the former case, the position of the contact surface in the vertical direction can be determined so that the columnar body, the buffer member, and the cylindrical member are in the desired positional relationship, and the lower end surface of the buffer member is prevented from moving downward from the position where the contact surface is fixed. On the other hand, in the latter case, the lower limit position of the range in which the contact surface can move back and forth can be determined so that the columnar body, the buffer member, and the cylindrical member are in the desired positional relationship, and the lower end surface of the buffer member is prevented from moving downward from the lower limit position of the contact surface.

[0125] FIG. 7 is a flowchart showing each step executed in the first method. When the first method is started, first, in step S10, the first step described above is executed, and a buffer member is disposed on the outer surface of the columnar body. For example, a buffer member such as a sheet-like buffer mat is wound around the outer surface of a columnar body such as a columnar catalyst carrier. If necessary, the buffer member may be fixed by, for example, a combustible tape or the like. Further, for example, a wire net ring (a ring-shaped member composed of a net made of thin metal wires) may be mounted adjacent to the buffer member.

[0126] Next, proceed to step S20, and the second step described above is performed. The columnar body having the buffer member disposed on its outer surface in the first step described above is supported by the first support portion in a posture in which the axial direction of the columnar body is parallel to the vertical direction. Typically, the columnar body is placed on the first support portion so that the lower end surface of the columnar body abuts on the top surface of the support base of the first support portion.

[0127] Next, proceed to step S30, and the third step described above is performed. Above the columnar body supported by the first support portion in the first step described above, a cylindrical member is supported by the second support portion in a coaxial posture with the columnar body. For example, a second support portion having the same configuration as the guide jig provided in the press-fitting device (conventional device 1) described in Patent Document 1 mentioned above is arranged above the columnar body so as to be coaxial with the columnar body, and the cylindrical member is placed on this second support portion.

[0128] Next, proceed to step S40, and the above-described fourth process is performed. The columnar body supported by the first support portion and the cylindrical member supported by the second support portion are driven by the press-fitting portion so as to approach each other in the vertical direction, and the assembly of the columnar body and the buffer member is press-fitted into the inside of the cylindrical member.

[0129] In the first method, even when the buffer member moves downward with respect to the columnar body during the press-fitting performed in the fourth process as described above, the lower end surface of the buffer member is prevented from moving downward from the contact surface by the contact between the lower end surface of the buffer member and the contact surface.

[0130] <Effect> As described above, in the first method, even when the buffer member moves downward with respect to the columnar body during press-fitting, the contact between the lower end surface of the buffer member and the contact surface of the contact jig can prevent or reduce the downward movement of the buffer member. As a result, it is possible to reliably prevent the lower end surface of the buffer member from moving downward beyond the desired position included in the first range. That is, according to the first method, when press-fitting a columnar body having a buffer member disposed on its outer surface into the inside of a cylindrical member, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be surely mounted so as to have the intended positional relationship, and the columnar body can be held at a predetermined position inside the cylindrical member.

[0131] <<Seventh Embodiment>> Hereinafter, a press-fitting method according to the seventh embodiment of the present invention (hereinafter, may be referred to as the "second method") will be described with reference to the drawings. As described in the explanation of the first apparatus, the contact surface may be fixed at a predetermined position included in the first range.

[0132] <Configuration> Therefore, the second method is the first method described above, and is a press-fitting method using the press-fitting device (second device) according to the second embodiment of the present invention described above. The second device is the first device described above, and is a press-fitting device characterized in that a contact jig is disposed such that a contact surface is fixed at a third position which is a predetermined position included in the first range. Since the configuration and operation of the second device have already been described in detail in the description of the second device, the description here is omitted.

[0133] <Effect> In the second method in which press-fitting is performed using the second device having the above-described configuration, it is possible to surely prevent the lower end surface of the buffer member from moving downward from the third position along with the press-fitting. Therefore, according to the second method, by determining the third position so that the columnar body, the buffer member, and the cylindrical member have a desired positional relationship, when press-fitting the columnar body having the buffer member disposed on the outer surface into the cylindrical member, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be more surely mounted so as to have the desired positional relationship, and the columnar body can be held at a predetermined position inside the cylindrical member.

[0134] <<Eighth Embodiment>> Hereinafter, a press-fitting method according to the eighth embodiment of the present invention (hereinafter, may be referred to as the "third method") will be described with reference to the drawings. As described in the description of the first device, the contact surface may be movable back and forth in the vertical direction over a predetermined range included in the first range.

[0135] <Configuration> Therefore, the third method is the first method described above, and is a press-fitting method using the press-fitting device (third device) according to the third embodiment of the present invention described above. The third device is the first device described above, and the contact jig is configured such that the contact surface is movable forward and backward in the vertical direction over a second range that is a range from the third position to the fourth position, and the contact jig is disposed such that the contact surface is located at the third position at the time when press-fitting is started. The third position is a predetermined position included in the first range, and the fourth position is a position included in the first range and located below the third position. Further, the third device further includes a biasing portion that drives the contact jig so that the contact surface is biased upward. In addition, the biasing portion is configured such that the biasing force is smaller than the pressing force at least during a part of the period from the time when the lower end surface of the buffer member contacts the contact surface to the time when press-fitting ends. Here, the biasing force is the force applied upward to the contact surface by the biasing portion, and the pressing force is the force with which the lower end surface of the buffer member presses the contact surface downward. Since the configuration and operation of the third device have already been described in detail in the description of the third device, the description here is omitted.

[0136] <Effect> In the third method in which press-fitting is performed using the third device having the above-described configuration, during at least a part of the period from the time when the lower end surface of the buffer member contacts the contact surface to the time when press-fitting ends, the contact surface is pressed downward by the lower end surface of the buffer member and the contact jig moves downward. However, as described above, the contact surface does not move below the fourth position, and the lower end surface of the buffer member also does not move below the fourth position. Therefore, it is possible to reliably prevent the lower end surface of the buffer member from moving below the fourth position along with press-fitting. Therefore, according to the third method, by determining the fourth position so that the column body, the buffer member, and the cylindrical member have the intended positional relationship, when press-fitting a column body having a buffer member disposed on its outer surface into the inside of a cylindrical member, regardless of the magnitude relationship of the friction coefficients among the column body, the buffer member, and the cylindrical member, these can be more reliably mounted so as to have the intended positional relationship, and the column body can be held at a predetermined position inside the cylindrical member.

[0137] Also, as described in the description of the third device, in the third device, it is possible to reduce the shrinkage rate in the vertical direction of the buffer member accompanying press-fitting. Therefore, according to the third method in which press-fitting is performed using the third device, even when an assembly in which a columnar body having a buffer member disposed on its outer surface is press-fitted into a cylindrical member is used in applications where, for example, an increase in the bulk density of the buffer member accompanying press-fitting is not desirable, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be more reliably mounted in the desired positional relationship to manufacture the assembly.

[0138] <<Ninth Embodiment>> Hereinafter, a press-fitting method according to the ninth embodiment of the present invention (hereinafter, may be referred to as the "fourth method") will be described with reference to the drawings. As described in the description of the fourth device, depending on the application of the assembly in which a columnar body having a buffer member disposed on its outer surface is press-fitted into a cylindrical member, it may be desirable to adjust the bulk density of the buffer member (particularly in the vicinity of the lower end surface) to a desired value as the press-fitting process progresses.

[0139] <Configuration> Therefore, the fourth method is the first method described above, which is a press-fitting method using the press-fitting device (fourth device) according to the fourth embodiment of the present invention described above. The fourth device is the first device described above, and the contact jig is configured such that the contact surface is movable in the vertical direction over a second range that is a range from the third position to the fourth position, and the contact jig is disposed such that the contact surface is located at the third position at the time when press-fitting is started. The third position is a predetermined position included in the first range, and the fourth position is a position included in the first range and located below the third position. In addition, the fourth device further includes a drive unit that drives the contact jig so that the contact surface moves at a predetermined speed over the second range. Since the configuration and operation of the fourth device have already been described in detail in the description of the fourth device, the description here is omitted.

[0140] <Effect> In the fourth method in which press-fitting is performed using the fourth device having the above-described configuration, by controlling the moving speed of the contact surface in the second range described above by the drive unit, the shrinkage rate in the vertical direction of the buffer member accompanying press-fitting is controlled, and the bulk density of the buffer member (particularly near the lower end surface) at the completion of press-fitting can be easily set to a desired value.

[0141] Furthermore, as described above, by appropriately setting the range in which the support pillar is driven by the drive unit, the third position, which is the upper limit position of the second range, which is the movable range of the contact surface that can move forward and backward in the vertical direction, and the fourth position, which is the lower limit position, can be changed. Therefore, for example, when any one of the pillar body, the buffer member, and the cylindrical member that constitute the integrated body integrated by press-fitting using the fourth device is changed due to a change in brand or the like, the third position and the fourth position can be easily changed by setting the drive unit. As a result, according to the fourth method, for example, the labor, time, and cost required for changing the manufacturing conditions accompanying a change in brand or the like can be reduced.

[0142] <<Tenth Embodiment>> Hereinafter, a press-fitting method according to the tenth embodiment of the present invention (hereinafter, may be referred to as the "fifth method") will be described with reference to the drawings. As described in the description of the fifth device, depending on the use of the integrated body in which the pillar body with the buffer member disposed on the outer surface is press-fitted into the cylindrical member, it may be desirable to adjust the bulk density of the buffer member (particularly near the lower end surface) to a desired value as the press-fitting process progresses.

[0143] <Configuration> Therefore, the fifth method is a press-fitting method using the press-fitting device (fifth device) according to the fifth embodiment of the present invention described above, which is any one of the first to fourth methods described above. The fifth device is any one of the first to fourth devices described above, and is a press-fitting device characterized in that the support base is configured such that the support surface, which is the top surface of the support base, is tiltable within a predetermined angle range with respect to the horizontal plane. The configuration and operation of the fifth device have already been described in detail in the description of the fifth device, so the description here is omitted.

[0144] <Effect>

Example

[0145] Hereinafter, a press-fitting device and a press-fitting method according to an embodiment of the present invention (hereinafter, may be referred to as "embodiment device" and "embodiment method", respectively) will be described in detail with reference to the drawings.

[0146] FIG. 8 is a schematic cross-sectional view showing the configuration of the embodiment device and the press-fitting process performed using the embodiment device. In FIG. 8, only the vicinity of the lower end surface of the column body is enlarged and drawn for the purpose of showing in detail the configuration of the embodiment device and the positional relationship among the column body, the buffer member, and the cylindrical member. Further, the left side of the axis AX of the column body toward FIG. 8 represents the time point before the lower end surface of the buffer member abuts against the abutting surface of the abutting jig, and the right side of the axis AX of the column body represents the time point when the press-fitting is completed and the buffer member is mounted at the expected position.

[0147] The configuration of the embodiment device will be described in detail below with reference to FIG. 8. A first support portion 110 constituting the embodiment device 106 is set on the upper portion of a base (not shown). Specifically, an engaging portion 116 (a member constituting a chuck) bulging downward from a support base 112 constituting the first support portion 110 is chucked inside a hole formed in the base, whereby the support base 112 is firmly fixed on the base. Further, a support base 111 is placed on the support base 112 and firmly fixed by a central through bolt 117.

[0148] And the contact portion 141 (constituting the contact jig 140), which is a cylindrical member, is floating-mounted on the support base 112 via the spring b constituting the biasing portion 144. As shown on the left side of the axis AX of the column body 200, before the lower end surface of the buffer member 300 contacts the contact surface 140a, which is the top surface of the contact portion 141, the contact jig 140 is pressed upward by the repulsive force of the spring b and the movement of the contact surface 140a upward beyond the third position P3, which is the upper limit position, is blocked by the bolt head serving as the stopper 143. That is, the contact jig 140 is configured such that the contact surface 140a is positioned at the third position P3 when the press-fitting starts.

[0149] Also, a convex spherical surface portion 111c is provided upward at the center of the top surface of the support portion 111b, and this spherical surface portion 111c is fitted into a hole formed at the center of the bottom surface of the mounting portion 111a (base) located above. Thereby, the mounting portion 111a and the support portion 111b are connected like a spherical bearing to constitute the support base 111. Therefore, the mounting portion 111a is configured to be tiltable with the spherical surface portion 111c as a fulcrum. That is, the support base 111 is configured such that the support surface, which is the top surface of the mounting portion 111a constituting the support base 111, is tiltable with respect to the horizontal plane.

[0150] The range of the above-mentioned tilt is restricted by a plurality of stoppers erected circumferentially on the upper surface of the support portion 111b. Specifically, the tilt is restricted to a predetermined range (for example, ±1° with respect to the horizontal plane, etc.) by the size of the gap between the bottom surface of the mounting portion 111a and the upper end of the stopper. That is, the stopper constitutes the tilt restricting portion 114 described above. Further, on the upper surface of the support base 111b, a plurality of sets of spring a and through bolts are arranged alternately in a circumferential shape with a plurality of stoppers, and they serve to suppress the tilt of the mounting portion 111a and maintain the support surface, which is the top surface of the mounting portion 111a, horizontally. That is, the set of spring a and through bolt constitutes the horizontal maintaining portion 115 described above.

[0151] As described above, according to the tilting control unit 114 and the horizontal maintaining unit 115, even when the lower end surface of the column body 200 is inclined with respect to the horizontal rather than perpendicular to the axis of the column body, the support surface of the placement unit 111a is inclined according to the angle of the lower end surface of the column body 200, so that the lower end surface of the column body 200 and the support surface can be in surface contact. As a result, it is possible to reduce the risk of problems such as breakage of the column body due to stress concentration caused by local contact between the lower end surface of the column body 200 and the support surface.

[0152] On the other hand, the second support portion 120 included in the example apparatus 106 has the same configuration as the guide jig included in the press-fitting apparatus (conventional apparatus 1) described in Patent Document 1 mentioned above. Specifically, the second support portion 120 included in the example apparatus 106 is a cylindrical member having a tapered portion in which the cross-sectional area of the hollow guide portion gradually increases downward. The second support portion 120 supports the cylindrical member 400 in a coaxial posture with the column body 200 above the column body 200 supported by the first support portion 110.

[0153] The example method is a method of press-fitting a column body 200 with a buffer member 300 wound around its outer surface into the inside of a cylindrical member 400 using the example apparatus 106 having the above-described configuration. Specifically, according to the flowchart illustrated in FIG. 7, a buffer mat 300 is wound around the outer surface of the column body 200 (step S10), and the column body 200 is placed on the top surface of the first support portion 110 (the support surface of the placement portion 111a) (step S20). Then, the cylindrical member 400 is supported by the second support portion 120 in a coaxial posture with the column body 200 above the column body 200 supported by the first support portion 110 (step S30), and the cylindrical member 400 placed on the second support portion 120 is lowered from above the column body 200 by a press-fitting portion (not shown), so that the combination of the column body 200 and the buffer member 300 is press-fitted into the inside of the cylindrical member 400 while compressing the buffer member 300 by the tapered portion of the second support portion 120 (step S40).

[0154] Figures 9 to 14 are schematic cross-sectional views showing the positional relationships of the column body 200, the first support portion 110, the second support portion 120, the contact jig 140, and the buffer member 300 and the cylindrical member 400 in each step included in the press-fitting process (the above step S40) executed using the example apparatus 106.

[0155] First, FIG. 9 is a schematic cross-sectional view showing step 1 (the starting point of press-fitting) of the press-fitting process executed using the example apparatus 106. In FIG. 9, the cylindrical member 400 is supported by the second support portion 120 in a coaxial posture with the column body 200 above the column body 200 supported by the first support portion 110 in the above-described step S30, and the positional relationships of the respective constituent members at the time when the above-described step S40 is started are shown. As shown in FIG. 9, in step 1, the lower end of the cylindrical member has not yet reached the upper end of the column body.

[0156] Next, FIG. 10 is a schematic cross-sectional view showing step 2 (the time point after the start of press-fitting and before the start of movement of the buffer member) of the press-fitting process. In step 2 shown in FIG. 10, the cylindrical member 400 placed on the second support portion 120 is lowered by a press-fitting portion (not shown), and although the vicinity of the upper end portion of the column body 200 around which the buffer member 300 is wound on the outer surface is press-fitted into the lower end portion of the cylindrical member 400, the downward movement of the buffer member 300 due to the press-fitting has not yet started.

[0157] Next, FIG. 11 is a schematic cross-sectional view showing step 3 (the time point after the start of movement of the buffer member) of the press-fitting process. In step 3 shown in FIG. 11, although the downward movement (displacement) of the buffer member 300 due to the press-fitting has started, the lower end surface of the buffer member 300 has not yet come into contact with the contact surface 140a of the contact jig 140.

[0158] As the press-fitting process further progresses, eventually the lower end surface of the buffer member 300 comes into contact with the contact surface 140a of the contact jig 140 (that is, the top surface of the contact portion 141 that constitutes the contact jig 140). FIG. 12 is a schematic cross-sectional view showing step 4 of the press-fitting process (when the lower end surface of the buffer member is in contact with the contact surface of the contact jig). In step 4 shown in FIG. 12, by the lower end surface of the buffer member 300 coming into contact with and pressing against the contact surface 140a, the buffer member 300 and the contact portion 141 move downward together.

[0159] As the press-fitting process further progresses, as shown on the right side of the axis AX of the column body 200 in FIG. 8, the lower end surface of the contact portion 141 comes into contact with the upper end surface of the support base 112. As a result, further downward movement of the contact portion 141 is blocked, so downward movement of the contact surface 140a, which is the top surface of the contact portion 141, below the fourth position P4 is also blocked. FIG. 13 is a schematic cross-sectional view showing step 5 of the press-fitting process (when the downward movement of the buffer member 300 and the contact portion 141 stops). Since the contact surface 140a cannot move further downward from the position at this time (that is, the fourth position P4), the lower end surface of the buffer member 300 also cannot move further downward from the fourth position P4.

[0160] Finally, FIG. 14 is a schematic cross-sectional view showing step 6 of the press-fitting process (when the cylindrical member 400 moves further downward and the press-fitting is completed). As described above for step 5, at this time, the lower end surface of the contact portion 141 has already come into contact with the upper end surface of the support base 112, and downward movement of the contact surface 140a, which is the top surface of the contact portion 141, below the fourth position P4 has already been blocked. Therefore, even during the period when the press-fitting process progresses from step 5 to step 6 and the cylindrical member 400 descends to the intended position, the lower end surface of the buffer member 300 cannot move further downward from the fourth position P4. That is, with the lower end surface of the buffer member 300 positioned at the fourth position P4, the positional relationship among the column body 200, the buffer member 300, and the cylindrical member 400 is fixed, and with the buffer member 300 clamped at the intended position between the column body 200 and the cylindrical member 400, the mounting by press-fitting of these members is completed.

[0161] As described above, in the example method which is a press-fitting method using the example apparatus, by determining the fourth position so that the columnar body, the buffer member, and the cylindrical member are in the intended positional relationship, when press-fitting the columnar body having the buffer member disposed on its outer surface into the cylindrical member, regardless of the magnitude relationship of the friction coefficients among the columnar body, the buffer member, and the cylindrical member, these can be reliably mounted so as to be in the intended positional relationship, and the columnar body can be held at a predetermined position inside the cylindrical member.

[0162] As described above, for the purpose of explaining the present invention, several embodiments and examples having specific configurations have been described with reference to the accompanying drawings at times. However, the scope of the present invention should not be construed as being limited to these exemplary embodiments and examples, and it goes without saying that appropriate modifications can be made within the scope of the matters described in the claims and the specification.

Explanation of Reference Numerals

[0163] 101, 102, 103, 104, 105, 106... Press-fitting devices, 110... First support portion, 111... Support base, 111a... Placing portion, 111b... Support portion, 111c... Spherical surface portion, 112... Support base, 113... Support column, 114... Tilting restriction portion, 115... Horizontal maintenance portion, 116... Engaging portion, 117... Through bolt, 120... Second support portion, 130... Press-fitting portion, 131... Pressing member, 132... Pressing column, 133... Actuator, 140... Contact jig, 140a... Contact surface, 141... Contact portion, 142... Support portion, 143... Stopper, 144... Biasing portion, 150... Driving portion, 200... Columnar body, 300... Buffer member, 400... Cylindrical member, 500... Pressing member, 600... Guide jig, 600a... Taper portion, 700... Support jig, 700a and 700b... Annular stepped portions, AX... Axis of the columnar body, P1... First position, P2... Second position, P3... Third position, P4... Fourth position, and a and b... Springs.

Claims

【Claim 1】 A first support portion having a support base that supports the column body from below in a posture in which the axial direction of the column body having a buffer member disposed on the outer surface is parallel to the vertical direction; A second support portion that supports the cylindrical member in a coaxial posture with the column body above the column body supported by the first support portion; A press-fitting portion that drives the column body supported by the first support portion and the cylindrical member supported by the second support portion to approach each other in the vertical direction to perform press-fitting of the set of the column body and the buffer member into the cylindrical member; A press-fitting device comprising: The press-fitting device further includes a contact jig that has a contact surface that is a surface facing the lower end surface of the buffer member in the vertical direction within a region between the inner peripheral surface of the cylindrical member and the outer surface of the column body in a vertical projection onto a horizontal plane, and is a member separate from the first support portion; The contact jig is configured not to interfere with either the cylindrical member or the second support portion during the period from the start to the end of the press-fitting, and is located in a first range that is a range from a first position that is the position of the lower end surface of the buffer member in the vertical direction before the press-fitting is performed to a second position that is the position of the lower end surface of the column body located below the first position in the vertical direction. The contact surface is fixed at a predetermined position included in the first range; The support base is configured such that a support surface that is the top surface of the support base is tiltable within a predetermined angle range with respect to the horizontal plane. Characterized by: A press-fitting device.

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