JP3448914B2 - Manufacturing method of assist grip - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an assist grip for holding a body when a passenger rides on a vehicle such as a vehicle, a ship, an airplane and the like. In particular, the present invention relates to a method for manufacturing an assist grip including a base material and a skin covering the base material. 2. Description of the Related Art Conventionally, as an assist grip having a skin, for example, as shown in FIG. 8, a grip having a pair of outer members 52, 52 joined to both sides of a core member 51 is known. Each outer member 52 has a three-layer structure including a base material 53, a foam layer 54, and a skin 55. Although not shown, there is also a two-layer structure including a base material and a skin. When manufacturing the assist grip 56 having the above-described structure, the core member 51 is formed by an injection molding method. On the other hand, each outer member 52 is formed by the following method. First, the skin 55 with the foam layer 54 is formed by a vacuum forming method. More specifically, a resin sheet, which is a molding material for the skin 55, and a foam sheet, which is a molding material for the foam layer 54, are integrally bonded in advance, and after being softened by heating, they are placed on a mold. It is covered. Air between the resin sheet and the mold is sucked by a vacuum pump or the like. By this suction, the resin sheet and the foam sheet are adsorbed on the molding surface of the mold and are shaped into a predetermined shape. After shaping, the resin sheet and the foam sheet are cooled and solidified, and are taken out of the mold. Then, a desired skin 55 with a foamed layer 54 is obtained. Subsequently, a base material 53 is formed inside the foam layer 54 by a stamping molding method shown in FIG.
In this stamping molding method, the skin 55 with the foam layer 54 is arranged in the molding recess 58a of the movable mold 58 that is separated upward from the fixed mold 57. Nozzle 5 of stamping molding machine
9 moves rightward as indicated by the two-dot chain line in FIG. 9, and the molten resin R for forming a base material hangs down from the nozzle 59 on the molding protrusion 57 a of the fixed mold 57. When a predetermined amount of the molten resin R hangs, the supply of the molten resin R is stopped, and the nozzle 59 is turned off as shown in FIG.
Move to the left of and return to the original position. The movable mold 58 is moved in the mold clamping direction (downward), and the molten resin R
7a and the foam layer 54 are compressed. When the fixed mold 57 and the movable mold 58 are clamped, the molten resin R is shaped into a predetermined shape. Thereafter, when the molten resin R is cooled and solidified, the base material 53 is formed, and as shown in FIG.
The outer member 52 including the foam layer 54 and the base material 53 is obtained. The outer member 52 obtained as described above.
Are arranged on both sides of the core material 51 so that the base material 53 faces the core material 51 as shown in FIG. Each outer member 52
Is pressed against the protrusion 51a of the core member 51, and in this state, the outer member 52 is vibrated in the left-right direction of the drawing at a predetermined frequency. Then, the temperature of the press contact portion rises, and the
1a and 52a are welded to each other. When welded in this manner, an assist grip 56 in which the core member 51 and the outer members 52 are integrated is obtained. In the assist grip 56, the core member 51 and the pair of outer members 52, 5
2, the two outer members 52, 52 are only in contact with each other. [0007] However, the conventional manufacturing method has the following various problems. First, at the time of forming the skin 55 with the foam layer 54 by the vacuum forming method,
The resin sheet and the foam sheet softened by heating are placed on the mold. At this time, a portion of the resin sheet and the foam sheet corresponding to the bent portion 60 of the skin 55 and the foam layer 54 is stretched more than a portion corresponding to a flat portion or a portion corresponding to a curved portion having the same curvature. . Then
The thickness of the bent portion 60 becomes smaller than the thickness of the other portions by the extension. Therefore, the skin 5 with the foam layer 54
5, the hardness (flexibility) of the skin 55 and the foam layer 54 varies depending on the thickness variation. Due to this variation, the feel when gripping the assist grip 56 differs depending on the region, and the sense of incongruity remains. Further, a substrate 53 formed by stamping molding is used.
In some cases, the molding may be performed with the molten resin R protruding from the skin 55. Therefore, in the assist grip 56 manufactured using the outer member 52 having the base material 53, the base material 53, which should be covered by the skin 55, is exposed on the surface, and the appearance may be impaired. Further, since the core member 51 and the pair of outer members 52, 52 formed separately are welded to each other, a seam (partition line L) is formed at the boundary between the outer skins 55 of the outer members 52, 52. It will inevitably remain, and the appearance will be impaired from this point as well. [0010] Further, since the number of parts of the assist grip 56 is large, the work of arranging each member at the time of stamping molding is troublesome, and the production cost is increased. The present invention has been made in view of the above-described circumstances, and an object thereof is to manufacture an assist grip that has a small variation in hardness due to a variation in skin thickness, has a good appearance, and can suppress an increase in manufacturing cost. It is to provide a method. [0011] In order to achieve the above object, the present invention comprises a base material and a skin covered around the base material, both ends of which are covered by shielding members. A method for manufacturing an assist grip, in which a tubular outer skin with both ends opened is formed by a blow molding method or an extrusion molding method, and thereafter, cuts are made at both ends of the outer skin.
To form a plurality of locking pieces , dispose the skin in a cavity between the fixed mold and the movable mold , and press each member with a pressing member.
Press the locking piece against the fixed type and the movable type, and
And locking the I, injecting molten resin from the open end of the epidermis, and to form the substrate into the epidermis by causing the molten resin is cooled and solidified. In the present invention, first, a skin is formed by a blow molding method or an extrusion molding method. The obtained skin has a circular tubular shape with both ends open, and there is no portion (bending portion) having a greatly different curvature. For this reason, the resin material is not greatly expanded locally, and a skin having a substantially uniform thickness is formed. The skin is disposed in a cavity between the fixed mold and the movable mold. Then, molten resin is injected from the open end of the skin. At this time, since the epidermis is in a tubular shape,
The injected molten resin does not protrude out of the skin from portions other than both ends of the skin. The molten resin injected into the skin is cooled. When the molten resin solidifies due to cooling,
A substrate is formed in the epidermis. Thus, an assist grip including the base material and the skin covered around the base material is manufactured. In this production, only one skin is required, and a core material is not required. For this reason, the number of parts is reduced as compared with the case where the assist grip is constituted by the core material and the pair of outer members (prior art). Accordingly, the number of man-hours for arranging each member in each manufacturing process is reduced. In the obtained assist grip, the base material is not exposed at most parts of the skin except for both ends. Further, the base material is exposed at both ends of the skin, but this portion is covered and covered by the shielding member, so that the exposed portion is not visible when the assist grip is used. Further, in a configuration in which the skin is divided into a plurality of parts and they are superimposed (prior art), a seam (partition line) appears at the joint. On the other hand, in the first invention, since the skin constituting the surface portion of the assist grip is formed in a tubular shape by the blow molding method or the extrusion molding method, the dividing line appears on the surface thereof. Never. Further, as described above, since the thickness of the skin is substantially uniform at any part, the hardness (flexibility) of the skin is small in the obtained assist grip. For this reason, the feel when the assist grip is gripped is almost the same at any part. In particular, in the present invention, after forming the skin, cuts are made at both ends of the skin to form a plurality of locking pieces. When the skin is arranged in the cavity, the locking piece is pressed by the pressing member against the fixed mold and the movable mold. This pressing locks the skin to the cavity. Therefore, both ends of the skin are kept open. For this reason, it is difficult to form a gap between the end of the skin and the fixed mold or between the end and the movable mold, and it is possible to suppress the molten resin from flowing into the gap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is embodied in a method for manufacturing an assist grip for a vehicle will be described below with reference to FIGS. FIG. 5 shows a part of the assist grip 1. The assist grip 1 includes a base material 2 made of a polypropylene resin and a skin 3 made of a vinyl chloride resin. The base material 2 includes a rod-shaped gripping portion 4 that is gently curved so as to protrude upward, and an attachment portion 5 that is bent at both ends (only one end is shown in FIG. 5) of the gripping portion 4. Each mounting portion 5 is provided with a bolt insertion hole 6. The outer skin 3 covers almost the entire gripping portion 4 of the base material 2. Both ends of the base material 2 including both mounting portions 5 are exposed from the skin 3. The vehicle body 7 of the assist grip 1
When attaching to the bolt insertion holes 6
, A bolt 8 is inserted, and the bolt 8 is fastened to the body 7. At this time, caps 9 as shielding members are attached to both ends of the assist grip 1. The exposed portion of the base material 2 in the assist grip 1 is covered by the cap 9. When using the assist grip 1 fixed to the body 7 in this way, to support the body,
The skin 3 is gripped by the occupant of the vehicle. At this time, the substrate 2
Although both ends are exposed from the skin 3, the cap 9
Invisible to the occupants because it is covered by. Next, a method of manufacturing the assist grip 1 having the above configuration will be described. First, the skin 3 is formed by a blow molding method or an extrusion molding method. The blow molding method is a thermoplastic resin (in this case, polyvinyl chloride resin)
Is preformed into a tubular shape by extrusion or injection, is sandwiched by a mold, and is blown with air to expand and cool and solidify. In addition, the extrusion molding method mainly uses a thermoplastic resin (in this case, a polyvinyl chloride resin).
Is a method of continuously forming a molded article having the same cross section, such as a circular pipe, using the above method. In principle, the material is melted in a heating cylinder, and the molten resin is extruded from a die equipped in the heating cylinder using the extrusion pressure due to the rotation of the screw. The extruded molten resin is cooled and solidified by water or air, and then cut into a predetermined length. These methods are well-known resin molding methods,
The obtained skin 3 has a tubular shape, and does not have a portion (bending portion) having a large difference in curvature. For this reason, unlike the prior art in which the skin 55 with the foam layer 54 is formed by the vacuum forming method, in this embodiment, the resin material is not greatly expanded in part, and the thickness is substantially uniform at any part. The epidermis 3 is formed. Next, as shown in FIG. 2, a pair of first cuts 1 extending in the longitudinal direction of the skin 3 are formed at both ends of the skin 3.
1 and a pair of second cuts 12 perpendicular to the first cut 11 and extending in the circumferential direction of the skin 3. As shown in FIG. 3, a pair of locking pieces 13, 14 each having a square plate shape are formed on both ends of the skin 3 by the cuts 11, 12. Next, using the injection mold 15,
To form Here, the injection molding die 15 will be briefly described prior to the molding of the base material 2. As shown in FIGS. 1 and 4, the molding die 15 includes a fixed die 16 and a fixed die 16.
Movable mold 1 movably arranged up and down so as to contact and separate
7 A molding projection 18 is formed on the fixed mold 16, and a molding recess 19 is formed on the movable mold 17. When the movable mold 17 is brought into contact with the fixed mold 16 when the mold is clamped, a cavity (molding space) 21 for molding the base material 2 is formed in both dies 17 and 16. . A first pressing member 22 is disposed on the fixed die 16. The first pressing member 22 is moved forward and backward on the fixed die 16 by an actuator (not shown) such as a hydraulic cylinder. The movable die 17 is formed with a concave portion 23 which is opened at the lower surface thereof. In the concave portion 23, a second pressing member 24 having a hook portion 24a is housed so as to be able to protrude and retract. A compression coil spring 25 that constantly biases the second pressing member 24 in the protruding direction (downward in the drawing) is accommodated in the recess 23. When molding the base material 2 using the injection mold 15, the movable mold 17 is separated upward from the fixed mold 16 (opened) as shown in FIG. The first pressing member 22 is retracted and separated from the molding projection 18 of the fixed die 16. At this time, in the movable die 17, the second pressing member 24 is moved by the urging force of the compression coil spring 25 so that
From the bottom. The direction of the skin 3 is adjusted so that the locking pieces 13 and 14 are positioned vertically, and the skin 3 is arranged on the projection 18 of the fixed die 16 along the curved shape. At this time, the lower locking piece 14 is in a state of rising from the side surface 18 a of the molding projection 18. Thereafter, the first pressing member 22 is advanced to approach the forming projection 18. In the course of the advance, the lower locking piece 14 is pressed by the first pressing member 22 and is bent downward. When the first pressing member 22 has advanced most,
The lower locking piece 14 is sandwiched between the first pressing member 22 and the side surface 18 a of the molding projection 18. The movable die 17 is moved down simultaneously with or slightly after the advance of the first pressing member 22. In the initial stage of the downward movement, the second pressing member 24 is
And move together. Thereafter, when the second pressing member 24 comes into contact with the fixed die 16, further movement is restricted. At this time, since the movable mold 17 continues to move downward, as a result,
The second pressing member 24 enters the recess 23 against the urging force of the compression coil spring 25. During the immersion process, the hook portion 24a of the second pressing member 24 presses the upper locking piece 13 and is bent upward. When the second pressing member 24 is fully immersed, that is, as shown in FIG.
When the mold comes into contact with the fixed mold 16 and is clamped, the upper locking piece 13 is sandwiched between the hook portion 24a and the lower surface of the movable mold 17 simultaneously with the completion of the mold clamping. As described above, when the locking pieces 13 and 14 are pressed by the fixed mold 16 and the movable mold 17 by the pressing members 22 and 24, the skin 3 is immovably locked in the cavity 21. Further, both ends of the skin 3 are kept open. For this reason, also between the end of the skin 3 and the fixed mold 16,
A gap is hardly generated between the end and the movable mold 17. After the mold 15 is closed, the molten resin R is injected into the cavity 21 from a nozzle (not shown) of the injection molding machine. The molten resin R is injected from one open end 3 a of the skin 3. At this time, both upper and lower locking pieces 1
3 and 14 are locked by the fixed mold 16 and the movable mold 17, and the open end 3a of the skin 3 is held in an open state. Therefore, the flow of the molten resin R between the open end 3 a of the skin 3 and the molding protrusion 18 or between the open end 3 a and the molding concave portion 19 is suppressed. The molten resin R flows toward the other open end 3 b of the skin 3. Molten resin R
Reaches the open end 3b, the upper and lower locking pieces 13,
14 is locked to the fixed mold 16 and the movable mold 17. For this reason, the open end 3b and the forming protrusion 18
Or between the open end 3b and the molding recess 19 is prevented from flowing. Since the outer skin 3 is formed in a tubular shape, the injected molten resin R is applied to both open ends 3a, 3b of the outer skin 3.
It does not protrude outside the epidermis 3 from other places. Epidermis 3
The molten resin R injected into the inside and filled in the cavity 21 is cooled. When the molten resin R is solidified by cooling,
The base material 2 including the grip portion 4 and the mounting portion 5 is formed in the skin 3 and on both ends thereof. Thereafter, the movable mold 17 is moved upward to open the mold. As the movable die 17 moves upward, the compression coil spring 25
, The second pressing member 24 projects downward from the recess 23. Further, the first pressing member 22 is moved backward. By the movement of the two pressing members 22, 24, the upper and lower locking pieces 13,
14 is released. Then, the assist grip 1 placed on the fixed die 16 is taken out. The upper and lower locking pieces 13 and 14 are cut off as necessary. Thus, the assist grip 1 including the base material 2 and the skin 3 is manufactured. In the manufacture described above, only one skin 2 is required, and the core 51 is not required. For this reason, the number of parts is reduced as compared with the related art in which the assist grip 56 is constituted by the core member 51 and the pair of outer members 52, 52. Accordingly, the number of man-hours for arranging each member in each manufacturing process is reduced, and an increase in manufacturing cost is suppressed. In the obtained assist grip 1 of the present embodiment, the base material 2 is not exposed at most of the skin 3 except for both ends. The base material 2 is exposed at both ends of the skin 3, but this portion is covered and covered by the cap 9, so that the exposed portion is not visible when the assist grip 1 is used. Further, in the prior art in which the skin 55 is divided into a plurality of parts and they are superimposed, a dividing line L appears at the joining portion. On the other hand, in this embodiment, since the skin 3 constituting the surface portion of the assist grip 1 is formed in a tubular shape by the blow molding method or the extrusion molding method, the dividing line L is formed on the surface thereof. Will not appear. Further, as described above, since the thickness of the skin 3 is substantially uniform at any part, the hardness (flexibility) of the skin 3 is obtained in the obtained assist grip 1.
There is little variation. For this reason, the feel when the assist grip 1 is gripped is almost the same at any part. As described above, according to the present embodiment, various problems of the conventional assist grip 56 (variation in hardness due to variation in the thickness of the skin 55 and the foam layer 54, appearance of the dividing line L) Lowering the manufacturing cost due to a large number of parts) can be provided. The present invention is not limited to the configuration of the above-described embodiment, and may be arbitrarily changed without departing from the spirit of each invention as described below. (1) The locking pieces 1 at both ends of the skin 3 in the embodiment.
Instead of 3 and 14, a separate plug 26 having both ends opened as shown in FIG. 6 may be used to lock the skin 3 to the cavity 21. In this case, when the skin 3 is arranged in the cavity 21, the plug 2 is attached to both ends of the skin 3.
Fit part of 6. The molten resin R is injected from the plug 26 into the skin 3. In this alternative, plug 26
Is added as one component of the assist grip 1. (2) In the above embodiment, the skin 3 has a single-layer structure, but may have a two-layer structure. For example, a tubular foam layer may be formed on the inner peripheral surface of the skin 3 in the above embodiment. (3) A hollow portion may be provided in the base material 2 for the purpose of reducing the weight of the assist grip 1 and saving the material of the base material 2.
In this case, when injecting the molten resin R for forming the base material, the compressed gas is supplied into the molten resin R at the same time as the injection or at a timing slightly delayed. (4) The manufacturing method of the present invention may be applied to an assist grip of a vehicle such as a ship or an airplane in addition to the assist grip 1 for a vehicle. As described in detail above, according to the present invention, it is possible to form a skin having a substantially uniform thickness, and thus it is possible to reduce variations in hardness due to variations in the thickness of the skin. In addition, the feel when gripping the assist grip can be enhanced. In addition, since the surface portion of the assist grip is formed of a tubular skin, it is possible to prevent a dividing line from appearing on the surface portion and to prevent the base material from being exposed, thereby improving the appearance. Further, since the assist grip can be configured with a small number of parts, the number of man-hours at the time of manufacturing can be reduced, and an increase in manufacturing cost can be suppressed. In particular, since the skin is locked in the cavity by the pressing member, both ends of the skin are held open and the gap between the end of the skin and the fixed mold or between the end and the movable mold is maintained. It is possible to suppress the molten resin from flowing into the space, reliably prevent the base material from being exposed on the skin, and improve the appearance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view showing an arrangement state of a skin when a fixed mold and a movable mold are clamped in one embodiment of the present invention. FIG. 2 is a perspective view of a skin with cuts at both ends in one embodiment. FIG. 3 is a perspective view of a skin having locking pieces formed at both ends in one embodiment. FIG. 4 is a partial cross-sectional view showing an arrangement state of a skin when a fixed mold and a movable mold are opened in one embodiment. FIG. 5 is a partial cross-sectional view of an assist grip according to one embodiment. FIG. 6 is a partial cross-sectional view showing an arrangement state of a skin when a fixed type and a movable type are clamped in another example in which a plug is fitted into an end of the skin instead of a locking piece. FIG. 7 is a cross-sectional view of an outer member according to the related art. FIG. 8 is a sectional view of an assist grip according to the related art. FIG. 9 is a partial cross-sectional view showing a state before clamping a fixed mold and a movable mold in a conventional technique of molding a base material by a stamping molding method. [Description of Signs] 1 ... Assist grip, 2 ... Base material, 3 ... Skin, 3a ... Open end, 9 ... Cap as a shielding member, 11 ... First cut, 12 ... Second cut, 13, 14 ... Lock Piece, 16
... fixed type, 17 ... movable type, 21 ... cavity, 22 ... first pressing member, 24 ... second pressing member, R ... molten resin

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroaki Tokai 1 Ochiai Nagahata, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture Toyota Gosei Co., Ltd. Inside (72) Inventor Hideki Ito 1 Ochiai Nagahata, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. (72) Inventor Masahiro Mineki 1 Ochiai Ogata, Kasuga-cho, Nishi-Kasugai-gun, Aichi Prefecture Toyoda Gosei Co., Ltd. (72) Inventor Masao Tanaka 1 Ochiai Ogata, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture (56) References JP-A-2-88335 (JP, A) JP-A-3-541 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45 / 14 B29C 45/26 B60N 3/02

Claims (1)

(57) [Claims] 1. A substrate (2) and a periphery of the substrate (2)
With a covered skin (3), both ends of which are shielding members
Made assist grip (1) covered by (9)
A method for making Both ends are opened by blow molding or extrusion molding
Forming a tubular outer skin (3),Then, the epidermis (3)
Make cuts (11, 12) at both ends of the
Forming pieces (13, 14),This skin (3) is fixed type
(16) and the cavity (21) between the movable mold (17)
ArrangementAnd each locking by the pressing members (22, 24)
The pieces (13, 14) are fixed (16) and movable (17)
To lock the skin (3) in the cavity (21)
Then, the molten resin (R) is removed from the open end (3a) of the skin (3).
Inject and cool and solidify this molten resin (R)
Forming the base material (2) in the skin (3)
Manufacturing method of assist grip.