JP5128652B2 - Resin tank and its manufacturing method - Google Patents

Description

  The present invention relates to a resin tank such as a reservoir tank for brake fluid of an automobile and a method for manufacturing the same.

  A master cylinder or a hydraulic booster in a vehicle brake system is provided with a reservoir tank for storing brake fluid. This type of reservoir tank is generally made of resin, and is manufactured by forming an upper member and a lower member by injection molding or the like and then integrating them by welding or the like.

  By the way, the shape of the reservoir tank differs not only by the vehicle manufacturer but also by the vehicle type even in the same vehicle manufacturer. In order to reduce the cost in such a reservoir tank, it is preferable to share parts in a plurality of vehicle types. Japanese Patent Application Laid-Open No. 2006-035899 describes that the lower member of the reservoir tank having a different position of the liquid injection stopper is shared by providing a liquid level sensor or the like on the lower member. In this way, one type of lower member can be used for a plurality of vehicle types, and only one type of mold for molding the lower member may be used, which makes it possible to significantly reduce costs.

  Depending on the type of vehicle, the presence or absence of a brake fluid discharge port in the reservoir tank may differ. For example, an MT vehicle uses an exhaust port, but an AT vehicle may not use an exhaust port. Accordingly, when the reservoir tank is shared between the AT vehicle and the MT vehicle, it is conceivable to share the reservoir tank in which the discharge port is formed. For example, it is conceivable to form a cylindrical portion having an open end and use it as it is in the case of an MT vehicle, and to use it by thermocompression bonding the tip in the case of an AT vehicle. Alternatively, after forming the cylindrical portion with the tip open, the tip is closed by thermocompression bonding and used as it is in the case of an AT vehicle, and in the case of an MT vehicle, the blocking portion may be excised and used as a discharge port. Good. However, the thermocompression bonding of the tip of the cylinder part has a problem that the number of steps is increased, for example, another crimping die is required.

  In view of this, it is conceivable to share a reservoir tank formed integrally with a cylindrical portion whose tip is closed. In this case, it can be used as it is in the case of an AT vehicle, and in the case of an MT vehicle, the tip of the tube portion can be cut off and used as a discharge port. And molds can be shared. According to this method, the man-hour for cutting the tip of the cylinder portion increases, but the man-hour can be greatly reduced as compared with the above-described method of thermocompression bonding.

  However, in the case where the cylindrical portion whose tip is closed is formed integrally with the reservoir tank, an inner diameter pin for forming the inside of the cylindrical portion needs to be moved in and out from the inside of the reservoir tank. However, in a brake fluid reservoir tank or the like, as shown in FIG. 7, it may be difficult to secure a space for a distance necessary to allow the inner diameter pin 100 to enter and exit due to the presence of the vertical wall 202 or the like. In such a case, it is not possible to form the cylindrical portion 200 whose tip is closed.

  Further, on the outer peripheral surface of the cylindrical part 200, a hose or tube bulging part 201 for preventing the cylindrical part 200 from being inserted and for sealing is generally formed. In order to prevent the bulging portion 201 from being undercut, a slide core is formed so as to open on both sides in the direction perpendicular to the paper surface with the central axis of the cylindrical portion 200 in FIG. What is necessary is just to comprise a metal mold | die so that a mold parting line may come to the surface. However, burrs may occur at the part of the parting line, and if burrs are generated on the outer surface of the cylinder part 200, the burrs may damage the hose or tube inserted into the cylinder part 200.

JP 2006-035899 A

  The present invention has been made in view of the above circumstances, and it is intended to provide a resin tank that can be shared for a plurality of uses while having a cylindrical portion that is used as a discharge port, and that can reliably avoid defects caused by burrs. Objective. Another object of the present invention is to manufacture such a resin tank easily and stably.

  A feature of the resin tank of the present invention is a resin tank that is integrated after the upper member and the lower member are formed by molding, respectively, and at least one side wall of the upper member and the lower member is provided with an inner portion. A cylindrical portion that communicates and protrudes outward is integrally formed. The tubular portion is formed on the distal end side and bulges in the radial direction, and is formed on the distal end side from the bulged portion and closes the tubular portion. The closed portion is integrally formed, and at least the surface of the bulged portion has no parting line.

Also, the resin tank manufacturing method of the present invention is characterized in that the upper member and the lower member are integrated after being formed by molding, and at least one side wall of the upper member and the lower member communicates with the inside. And a cylindrical portion projecting outward is integrally formed, the cylindrical portion is formed on the distal end side and bulges in the radial direction, and a closed portion formed on the distal end side from the bulging portion and closing the cylindrical portion And a method of manufacturing a resin tank integrally comprising:
The cylinder side member having a cylinder part, which is one of the upper member and the lower member, includes a container part surrounded by a side wall and a cylinder part protruding from a part of the side wall, and the cylinder part has a cylinder part. The first and second molds and the second mold that are tilted so that the side wall facing the side wall and the extension line of the central axis of the cylinder part do not interfere and are clamped together when the cylinder part side member is molded, Using a slide core held so as to be slidable and a slide pin disposed so as to be able to advance and retreat in the second mold, at least the outer peripheral surface of the cylindrical portion is formed with the slide core, and the inner peripheral surface of the cylindrical portion with the slide pin Perform the molding process to mold,
After molding, after the slide pin is retracted and removed from the cylindrical portion, the first and second molds are opened to slide the slide core relative to the second mold in the direction opposite to the slide pin moving direction. The cylindrical portion is forcedly removed from the slide core by elastically deforming and entering the cylindrical portion space formed by the slide pin being removed.

  According to the resin tank of the present invention, it has the cylindrical portion whose tip is closed by the closing portion. Therefore, when the cylinder part is used as a discharge port or the like, it is possible to open the tip of the cylinder part by cutting the cylinder part between the bulging part and the closed part and cutting the closed part. However, the tank can be shared between the case where the cylindrical portion is used and the case where the cylindrical portion is not used. Moreover, the metal mold | die which shape | molds a tank can be shared. And since there is no mold parting line on the outer peripheral surface of at least the bulging portion of the cylindrical portion, at least the bulging portion does not have burrs. Therefore, when the hose or tube is inserted into the cylindrical portion, it is possible to avoid a problem that the hose or tube is damaged by the burr.

  According to the resin tank manufacturing method of the present invention, the cylindrical portion is inclined so that the side wall facing the side wall having the cylindrical portion and the extension of the central axis of the cylindrical portion do not interfere with each other. Can be used to easily mold the inner peripheral surface of the cylindrical portion. When the slide pin is retracted after molding, a space is formed inside the cylindrical portion, so that the bulging portion can be easily forcibly removed by the elastic deformation of the cylindrical portion and entering the space. Therefore, it is possible to design a mold so that at least the outer peripheral surface of the bulging portion does not generate a parting line, and it is possible to stably manufacture a resin tank having no burrs in at least the bulging portion of the cylindrical portion.

1 is an exploded perspective view of a resin tank according to an embodiment of the present invention. It is sectional drawing of the lower member used for the resin-made tanks based on one Example of this invention. It is sectional drawing which shows the metal mold | die for lower member used for the resin-made tanks which concern on one Example of this invention in the state at the time of mold clamping. It is sectional drawing which shows the metal mold | die for lower member used for the resin-made tanks based on one Example of this invention, and shows the state which made the slide pin retreat. It is sectional drawing which shows the metal mold | die for lower member used for the resin-made tanks concerning one Example of this invention, and shows the state of a mold opening middle stage. It is sectional drawing which shows the metal mold | die for lower member used for the resin-made tanks based on one Example of this invention, and shows in the state of a mold opening late stage. It is sectional drawing which shows an example of the manufacturing method of the lower member used for the conventional resin tank.

  The resin tank of the present invention comprises an upper member and a lower member, and each is integrated after molding by injection molding or the like. For integration, it is preferable that the openings of the container-like upper member and lower member are brought into contact with each other and welded by vibration welding method using ultrasonic waves, hot plate welding method, etc., but a sealing member such as a gasket is interposed. And can be mechanically integrated. The type of resin is not particularly limited, but can be selected from soft polyethylene, polypropylene, polyamide, PET, etc. to such an extent that can be easily removed as described later.

  At least one side wall of the upper member and the lower member is integrally formed with a cylindrical portion that communicates with the inside and projects outward. The cylindrical portion serves as a passage for guiding the liquid stored in the tank to the outside. The cylindrical portion may have its central axis perpendicularly intersecting the side wall surface, and is inclined so that the side wall facing the side wall having the cylindrical portion and the extension line of the central axis of the cylindrical portion do not interfere with each other. May be. Even if the central axis of the cylindrical portion intersects the side wall surface perpendicularly, the inner peripheral surface of the cylindrical portion can be formed using a slide core if there is sufficient space inside the upper member or the lower member. . Further, when there is not enough space inside the upper member or the lower member, the side wall facing the side wall having the cylindrical portion and the extension line of the central axis of the cylindrical portion do not interfere with each other as in the manufacturing method of the present invention. The cylindrical portion can be formed by inclining the cylindrical portion and forming the inner peripheral surface of the cylindrical portion using a slide pin.

  The cylindrical portion integrally includes a bulging portion that is formed on the distal end side and bulges in the radial direction, and a closing portion that is formed on the distal end side from the bulging portion and closes the cylindrical portion. The bulged portion functions as a hose or tube retaining member inserted into the cylindrical portion, and generally bulges from 0.5 mm to 1.0 mm from the outer surface of the cylindrical portion. For tanks with specifications that do not use the cylinder part, use the cylinder with a closed part. For tanks that use the cylinder part, cut the cylinder part between the bulging part and the closed part and close it. It is used after forming an opening at the tip of the cylindrical part by excising the part.

  And the resin-made tank of this invention does not have a parting line in the surface of the at least bulging part of a cylinder part. Therefore, since at least the surface of the bulging portion does not have burrs, problems due to burrs can be prevented. It is necessary that at least the outer surface of the bulging portion does not have a parting line, but it is desirable that no parting line be provided on the outer peripheral surface of the cylindrical part.

  The manufacturing method of the present invention is a manufacturing method of the resin tank of the present invention described above, and a first mold and a second mold that are clamped together, a slide core that is slidably held in the second mold, Molding is performed using a mold provided with a slide pin disposed in the second mold so as to be able to advance and retreat. The cylindrical portion may be formed on either the upper member or the lower member, but a member having the cylindrical portion is referred to as a cylindrical portion side member. The cylindrical part side member is composed of a container part surrounded by a side wall and a cylindrical part protruding from a part of the side wall, and the cylindrical part has a side wall facing the side wall having the cylindrical part and a central axis of the cylindrical part. The central axis is inclined at an acute angle with respect to the sidewall surface so as not to interfere with the extension line.

  The molding step can be performed using an injection molding method. In this molding step, most of the outer surface of the container part is molded with the first mold, and the inner surface of the container part is molded with the second mold. Further, at least the outer peripheral surface of the tube portion is formed with the slide core, and the inner surface of the tube portion is formed with the slide pin advanced from the second mold. Since the cylindrical portion is inclined so that the side wall facing the side wall having the cylindrical portion and the extension of the central axis of the cylindrical portion do not interfere with each other, the slide pin is prevented from interfering with the cavity and the first mold. Yes.

  After the molding, the slide pin is first retracted and removed from the cylindrical portion, and then the first mold and the second mold are opened. Then, following the movement of the mold opening, the slide core slides relative to the second mold. Here, since the moving direction of the slide core is the opposite direction to the moving direction of the slide pin, the cylindrical portion formed on the outer peripheral surface by the slide core comes out of the slide core. In order to move the slide core in this manner, the slide core can be easily engaged with an angular pin protruding from the first mold.

  At this time, the bulging portion formed in the cylindrical portion is undercut, but the bulging amount of the bulging portion is small, and the slide pin is pulled out so that the cylinder is formed in the space formed inside the cylindrical portion. By allowing the portion to elastically deform and enter, the tube portion can be forcibly removed without being damaged. Then, the cylinder part side member which is an upper member or a lower member which comprises the resin-made tank of this invention is manufactured by releasing a molded article from a 2nd type | mold.

  Hereinafter, embodiments of the present invention will be described specifically by way of examples.

  FIG. 1 is an exploded perspective view of a resin tank according to the present embodiment, and FIG. 2 is a sectional view of a lower member. This tank is a brake fluid reservoir tank, which is composed of a polypropylene upper member 1 and a polypropylene lower member 2, and the upper member 1 and the lower member 2 are welded and integrated by vibration welding. Yes.

  The lower member 2 has a container part 20 and a cylinder part 21 in which brake fluid is stored. The container part 20 includes a pair of side walls 22 and 23 facing each other, and the cylindrical part 21 projects outward from the side wall 23. As shown in FIG. 2, the cylindrical portion 21 has a tip so that the central axis passes through a position away from the end of the side wall 22 as shown in FIG. 2 so that the central axis does not interfere with the side wall 22. Inclined downward. The tubular portion 21 has a bulging portion 24 formed on the distal end side, and a blocking portion 25 formed further on the distal end side of the bulging portion 24. Accordingly, the inside of the cylindrical portion 21 communicates with the container portion 20 up to the position of the closing portion 25, and only the tip is closed by the closing portion 25. The outer peripheral surface of the cylinder part 21 has no parting lines and no burrs throughout.

  The reservoir tank according to the present embodiment can be used as it is for a vehicle type that does not require a discharge port such as an AT vehicle. Further, by separating between the closed portion 25 and the bulging portion 24, the cylindrical portion 21 can be used as a brake fluid discharge port, and can be used for a vehicle type that requires a discharge port such as an MT vehicle. Therefore, the reservoir tank can be shared by the vehicle type that requires the discharge port and the vehicle type that does not need the discharge port, and the number of parts can be reduced. In addition, a mold for manufacturing the reservoir tank can be shared, and the mold cost can be reduced.

  Since the cylindrical portion 21 has no burr on the outer peripheral surface including the bulging portion 24, the hose and the tube inserted after the closed portion 25 is cut off are not damaged.

  Next, the manufacturing method of the above-described lower member 2 will be described below.

  FIG. 3 shows a schematic sectional view of a mold used for manufacturing the lower member 2. This mold is a mold for injection molding, and is a fixed mold 3 corresponding to the first mold according to the present invention, a movable mold 4 corresponding to the second mold according to the present invention, a slide core 5, and a slide pin. 6 mainly.

  In the movable mold 4, a slider 50 is slidably held by a grooved engagement (not shown), and a slide core 5 is fixed to the slider 50. An angular pin 30 protruding from the fixed mold 3 is engaged with the slider 50 and the slide core 5. The slide core 5 is formed with a cylindrical hole cavity 51 for forming the outer surface of the cylindrical portion 21, and the cylindrical hole cavity 51 communicates with a main cavity 31 formed between the fixed mold 3 and the movable mold 4. ing.

  The main cavity 31 is for molding the container portion 20 of the lower member 2, and the cavities 32 and 33 forming the side walls 22 and 23 are formed substantially parallel to the mold opening direction of the fixed mold 3 and the movable mold 4. Yes. Therefore, the central axis direction of the cylindrical hole cavity 51 forming the cylindrical portion 21 intersects the mold opening direction of the fixed mold 3 and the movable mold 4. The sliding movement direction of the slider 50 is parallel to the central axis direction of the cylindrical hole cavity 51.

  The slide pin 6 is driven forward and backward by a hydraulic cylinder device 60 fixed to the movable die 4. The advancing / retreating drive direction is parallel to the central axis direction of the cylindrical hole cavity 51 and intersects the mold opening direction of the fixed mold 3 and the movable mold 4. Further, the center axis of the slide pin 6 and the center axis of the cylindrical hole cavity 51 coincide with each other, and the hydraulic cylinder device 60 is driven to advance into the cylindrical hole cavity 51 and retreat from the cylindrical hole cavity 51. The cylindrical portion 21 is designed so that its central axis does not interfere with the side wall 22, so that the slide pin 6 can advance and retreat without interfering with the fixed mold 3 and the main cavity 31.

  At the time of injection molding, molding is performed in the clamping state shown in FIG. 3, the container part 20 is molded in the main cavity 31, and the cylinder part 21 is molded between the cylindrical hole cavity 51 and the slide pin 6. .

  After molding, the hydraulic cylinder device 60 is first driven, and the slide pin 6 is retracted from the cylindrical hole cavity 51 as shown in FIG. As a result, a space 26 is formed inside the cylindrical portion 21.

  Subsequently, as shown in FIG. 5, when the fixed mold 3 and the movable mold 4 are opened and the movable mold 4 moves downward in the drawing, the slide core 5 and the slider 50 are moved away from the container portion 20 by the engagement of the angular pin 30. The cylinder portion 21 is slid in the direction with respect to the movable mold 4 and the cylindrical portion 21 tends to come out of the slide core 5. At this time, although the bulging portion 24 is undercut, it can be forcibly removed by elastically deforming in the diameter reducing direction so that the cylindrical portion 21 enters toward the space 26.

  After the mold opening further proceeds, as shown in FIG. 6, the ejector pin (not shown) protrudes from the mold surface of the movable mold 4 and the lower member 2 is moved from the movable mold 4 after the cylindrical portion 21 is removed from the cylindrical hole cavity 51. Mold is released. Then, the upper member 1 and the lower member 2 separately formed by injection molding are welded, and the reservoir tank according to the present embodiment is manufactured.

  That is, according to the manufacturing method of the present embodiment, it is possible to easily form the cylindrical portion 21 whose tip is closed. Since the cylindrical portion 21 can be easily forcibly removed, it is possible to reliably avoid the occurrence of burrs on the outer peripheral surface of the cylindrical portion 21.

  The resin tank and the manufacturing method thereof according to the present invention can be used for all tanks having a cylindrical port, such as a reservoir tank of a brake fluid exemplified in the embodiment, a washer liquid tank, a shower toilet water tank, and the like.

1: Upper member 2: Lower member 3: Fixed type (first type) 4: Movable type (second type)
5: Slide core 6: Slide pin
20: Container part 21: Tube part
22, 23: Side wall 24: Swell
25: Blocking part 26: Space

Claims (5)

A resin tank that is integrated after forming the upper member and the lower member by molding,
At least one side wall of the upper member and the lower member is integrally formed with a cylindrical portion that communicates with the inside and projects outward.
The tubular portion integrally includes a bulging portion formed on the distal end side and bulging in the radial direction, and a closing portion formed on the distal end side from the bulging portion and blocking the tubular portion, and at least the bulging portion. A resin tank characterized by having no parting line on the surface of the protruding portion.   2. The resin tank according to claim 1, wherein the cylindrical portion is inclined so that a side wall facing the side wall having the cylindrical portion and an extension line of a central axis of the cylindrical portion do not interfere with each other.   The resin tank according to claim 1 or 2, which is a reservoir tank for storing brake fluid of an automobile. The upper member and the lower member are integrated after being formed by molding, and at least one side wall of the upper member and the lower member is integrally formed with a cylindrical portion that communicates with the inside and protrudes outward. The cylindrical portion is integrally formed with a bulging portion that is formed on the distal end side and bulges in the radial direction, and a closing portion that is formed on the distal end side from the bulging portion and closes the cylindrical portion. A tank manufacturing method comprising:
The cylinder part side member having the cylinder part, which is one of the upper member and the lower member, includes a container part surrounded by a side wall and the cylinder part protruding from a part of the side wall. Is inclined so that the side wall opposite to the side wall having the cylindrical portion does not interfere with the extension of the central axis of the cylindrical portion,
When forming the cylindrical part side member, the first mold and the second mold that are clamped together, a slide core that is slidably held by the second mold, and disposed so as to be able to advance and retreat in the second mold. Using the slide pin, and at least forming the outer peripheral surface of the cylindrical portion with the slide core and forming the inner peripheral surface of the cylindrical portion with the slide pin,
After the molding, the slide pin is retracted and removed from the cylindrical portion, and then the first mold and the second mold are opened to move the slide core in the direction opposite to the moving direction of the slide pin. Forcibly removing the cylindrical portion from the slide core by sliding the mold relative to the mold and elastically deforming and entering the cylindrical portion formed by the slide pin being removed. A method of manufacturing a resin tank characterized by the following.   The method for manufacturing a resin tank according to claim 4, wherein the cylindrical portion side member is the lower member.

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