JPH10239339A - Resin-sealed type rotation sensor and apparatus and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a positioning constitution of an insertion part, and facilitate development and enhance cost efficiency of an insert mold, by melting an annular projection by a thermoplastic resin injected into the insert mold at a melting temperature to form a housing and welding the projection integrally with the housing. SOLUTION: A sharp end of a clamp pin in a mold is fitted in a supporting hole 27 at one side of a bobbin 22. An insert mold is closed, and a leading end part, of the clamp pin projecting to an inner face of the insert mold is inserted into the other supporting hole 27 preliminarily formed in a primary component, 31 (bobbin 22), thereby clamping (positioning) the primary component 31 not to move in the insert mold. The same thermoplastic resin as that of the bobbin 22 is injected to a cavity space in the closed insert mold, whereby a housing 32 which is to water-tightly enclose the primary component 31 is insert molded between the primary component 31 and insert mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed rotation sensor mounted on a vehicle body, for example, for detecting the number of rotations of an automobile wheel. The present invention relates to a resin-sealed rotation sensor capable of increasing the economical efficiency at the time of molding using a simplified mold device and providing an insert molded product having excellent watertightness, a manufacturing device thereof, and a manufacturing method thereof. .

[0002]

2. Description of the Related Art A normal rotation sensor mounted on a vehicle body and used, for example, to detect the number of rotations of a wheel is an electromagnetic pickup type sensor. In order to enhance the waterproof property, it is configured as a resin sealing mold by molding.

[0003] The structure of the above-mentioned resin-sealed rotation sensor is, for example, as shown in FIG. 8. Reference numeral 1 denotes a hollow resin bobbin. , A spacer 4, and a pickup coil (magnetic change detection coil) 5 is wound around the outer periphery of the bobbin 1 so as to correspond to the peripheral surface of the pole piece 2. . Further, the other end of the terminal 6, one end of which is connected to the terminal of the pickup coil 5, is supported along the outside of the bobbin 1 and is also formed in a watertight manner with a part of the outer peripheral surface of the bobbin 1. It is configured to be located inside the housing part 7. Reference numeral 8 denotes a cover for protecting the outer peripheral portion of the coil 5 through an O-ring 9 in a watertight manner.

[0004] In the process of manufacturing the resin-sealed rotation sensor configured as described above, the pole piece 2, the magnet 3, and the spacer 4 are incorporated into a preformed bobbin 1, and further, the bobbin 1 is provided outside the bobbin 1. Winds the pickup coil 5, taping the outer periphery thereof 5A, and connects the terminal 6 to the terminal of the pickup coil 5 to obtain a primary component. Next, the primary component and the bush 10
In a state in which the resin is fixedly held in a predetermined insert mold, a thermoplastic resin is injected into the insert mold to form a housing part 7 integrally formed with a bobbin which is water-tightly joined to the outer surface of the bobbin 1. Is molded. Next, a cover 8 for protecting the coil 5 wound around the bobbin 1 is fitted in a watertight manner via an O-ring 9 to form a secondary configuration of a resin-sealed rotation sensor. .

In the molding process of the resin-sealed rotation sensor manufactured in this manner, when the primary component is set at a predetermined position in the insert mold, the primary component forms a secondary molded product. For this reason, a primary component positioning means is required for positioning so as not to be displaced (deflection) in the insert mold due to the injection power of the resin injected into the insert mold.

Conventionally, as a means for positioning a primary component housed in an insert mold, as shown in FIG. 9, a plurality of outer peripheral surfaces of the primary component housed in the insert mold are formed by the insert mold. Positioning means is employed which is clamped by a clamp pin 11 provided so as to be able to be inserted and removed so that the primary component is not displaced in the up, down, left, right, front and rear directions in the insert mold.

That is, when manufacturing a resin-sealed type rotation sensor for inserting a primary component, a clamp pin 11 for clamping the primary component in the mold is inserted into an insert molding die that houses the primary component. The mold is closed in a state where the primary component is sandwiched and positioned in the insert molding die by using the clamp pin.

Next, a thermoplastic resin is injected from the gate toward the cavity space into the closed insert mold. Next, during the resin flowing process while the thermoplastic resin is being pressed into the cavity space, each clamp pin 11 holding the primary component is pulled out while maintaining the injection pressure, and the injection resin is removed. Due to the holding pressure, a plastic resin is buried in the hole formed in the trace of pulling out the clamp pin 11, and the sealing is performed so that the trace of the clamp pin does not occur in the housing portion 7.

[0009]

However, the primary component parts housed in the insert molding die by using a plurality of clamp pins 11 provided so as to be able to be moved in and out (pulled out) by the insert molding die as described above. In the means for pinching and positioning, the structure for providing the plurality of clamp pins 11 in and out of the insert mold (pullable) and the operation mechanism for inserting and removing the clamp pins 11 are complicated. Is the temperature of the injection resin,
Since the curing speed of the injected thermoplastic resin changes depending on the mold temperature, the flow rate of the resin, and the like, it is often necessary to determine the setting conditions of the timing for pulling out the clamp pin 11 in the semi-cured state of the resin. Time is required, and it is difficult to maintain the conditions even after they are determined. This causes a long development time until the operation of the insert mold required to mold the resin-sealed rotation sensor is required. And lacked economic efficiency.

That is, if the timing of pulling out the clamp pin 11 is too early for the curing of the thermoplastic resin, a part of the softened resin is pulled out together with the clamp pin, and if it is too late, a weld line is generated. It is important to properly pull out the clamp pin 11 in relation to the curing speed of the thermoplastic resin, since a problem that the water tightness is reduced occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has a simplified configuration for positioning an insert part in an insert mold for manufacturing a resin-sealed rotation sensor, thereby facilitating the development of the insert mold. It is a first object of the present invention to develop a resin-encapsulated sensor capable of improving its economy and facilitating handling of an insert mold.

Further, according to the present invention, even though the positioning structure of the insert part is simplified, a resin seal capable of improving the watertightness between the insert part and the resin molded body surrounding the outer periphery of the insert part is provided. It is a second object of the present invention to provide a manufacturing apparatus for a stop rotation sensor.

Further, according to the present invention, despite the simplification of the positioning structure of the insert part, a resin seal capable of improving the watertightness between the insert part and the resin molded body surrounding the outer periphery of the insert part is provided. A third object is to provide a method for manufacturing a stop type rotation sensor.

[0014]

In order to achieve the first object, according to the first aspect of the present invention, a pole piece, a magnet and the like are provided inside, and a resin made of a resin for winding a magnetic change detecting coil is provided outside. At the appropriate position on the outer surface of the bobbin, a bottomed support hole into which the tip of a clamp pin provided in the insert mold is inserted is formed. On the outer surface of the resin bobbin, a hole surrounding the support hole is provided. When a plurality of annular ridges are integrally formed with the resin bobbin and the housing surrounding the resin bobbin is insert-molded, the annular ridge is inserted into an insert mold so as to form the housing. It is characterized in that it is a resin-sealed rotation sensor that is melted at the melting temperature of the injected thermoplastic resin and is welded integrally with the housing.

According to a second aspect of the present invention, a pole piece, a magnet, and the like are provided inside,
On the outside, a resin bobbin around which the magnetic change detection coil is wound is inserted, and in an insert mold for insert-molding a housing surrounding the outer periphery of the resin bobbin, on the cavity surface of the insert mold, At the time of closing the insert molding die, a plurality of clamp pins for holding an appropriate position on the outer peripheral surface of the resin bobbin positioned in the insert molding die are projected into both male and female molds of the insert molding die. The present invention is characterized in that it is a manufacturing device of the installed resin-sealed rotation sensor.

In order to achieve the third object, a third aspect is provided.
Then, a primary component consisting of a resin bobbin with a pole piece, a magnet, etc. inside, a coil for magnetic change detection wound around and a terminal bar attached to the outside, and this primary component inserted After being supported and stored in the mold by a plurality of clamp pins, a thermoplastic resin is press-fitted between the cavity surface of the insert mold and the primary component to integrally integrate a housing that surrounds the primary component in a watertight manner. In the method for manufacturing a resin-sealed rotation sensor to be molded, a support hole for clamping formed on the outer surface of the resin bobbin and one or more annular ridges surrounding the periphery of the support hole are integrally formed. A primary component having a resin bobbin is obtained, and then the primary component is inserted into the support hole with the pointed end of a clamp pin in one of the insert molding dies. Then, at the same time as closing the mold of the insert mold, the tip of the clamp pin formed in the cavity surface of the other mold in the insert mold is fitted into the support hole, and the primary component is inserted. Is clamped in an insert mold, and then, the same material as that of the resin bobbin is injected into the insert mold to surround the primary constituent parts, and the resin is formed by the heat of fusion of the injected resin. One or a plurality of annular ridges formed on the outer surface of the bobbin are melted to form a housing integrally welded with the annular ridges. Then, after injection molding of the housing, the mold is opened and clamped simultaneously. The method is characterized in that it is a method of manufacturing a resin-sealed rotation sensor for releasing a primary component from being clamped by a pin.

According to a fourth aspect of the present invention, in order to achieve the first object, in addition to the first and third aspects, the cross-sectional shape of the annular ridge is such that the inner wall surface of the annular ridge is inclined and the outer side is inclined. It is characterized in that it is a resin-sealed rotation sensor whose wall surface is formed upright.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS.

The present embodiment relates to a resin-sealed rotation sensor having a resin-sealed structure in order to enhance waterproofness. First, the structure of the resin-sealed rotation sensor 21 will be described.

Reference numeral 22 denotes a resin bobbin formed in a hollow cylindrical shape using, for example, a polyamide resin (for example, PA612 resin manufactured by DuPont). A pole piece 23 is provided in the hollow hole of the hollow bobbin 22. , Magnet 24,
The pickup coil 26 is wound around the bobbin 22 so as to correspond to the peripheral surface of the pole piece 23. At an appropriate position on the outer surface of the bobbin 22, a bottomed support hole 27 for fitting a tip portion of a clamp pin, which will be described later, is formed oppositely to the left and right. One annular ridge 28 formed annularly so as to surround the periphery of the support hole 27 is provided on the bobbin 22.
It is formed integrally with. As described above, the pole piece 23, the magnet 24,
The primary component 3 is provided with a spacer 25 inside, a pickup coil 26 wound around the bobbin 22, fixed with an insulating tape 29, and a terminal bar 30 connected to the pickup coil.
Assemble as 1.

Reference numeral 32 denotes a housing for sealing the primary component 31 in a watertight manner and integrally forming the male connector portion 33. The housing 32 is formed by insert molding means for inserting the primary component 31. The primary component 31 is formed integrally with the primary component 31 so as to surround the primary component 31 in a watertight manner. Reference numeral 34 denotes a mounting bush buried in the housing 32.

FIGS. 1 and 2 show a first embodiment.
In this embodiment, one annular ridge 28 is formed so as to surround the support hole 27. For example, as shown in FIG. 3, two annular ridges 28 are integrally formed so as to surround the support hole 27. As shown in FIGS. 4 and 5, in addition to the embodiment shown in FIGS. 1 and 3, the hole edge of the hollow hole forming the bobbin 22 is surrounded by the hole edge. One or a plurality of annular ridges 35 formed as described above are integrally formed.

The cross-sectional shape of the annular ridge 35 is a triangle having a sharp point as shown in the enlarged views of FIGS. 6 and 7, and the point angle θ is, for example, about 30 degrees. The protrusion length H of 28 is preferably about 1/5 of the thickness L of the housing 32 in which the rotation sensor 21 is to be sealed.

The cross-sectional shape of the annular ridges 28, 35 is such that the inner wall surfaces of the annular ridges 28, 35 are tapered and inclined, and the outer wall surfaces are formed upright, so that the resin is cured. At times, it is possible to prevent air from being trapped inside the annular ridges 28 and 35.

6 and 7, reference numeral 36 denotes a part of an insert mold for storing and holding the primary component 31. The cavity surface of the insert mold 36 is provided on the bobbin 22 of the primary component 31. A clamp pin 37 whose tip fits into the support hole 27 provided is protruded, and the tip of the clamp pin 37 fits into the support hole 27 provided on the bobbin 22 of the primary component 31. Thereby, the primary component 31 is clamped at a fixed position in the insert mold 36.

The above is the embodiment of the resin-sealed rotation sensor 21. Next, the manufacture of the resin-sealed rotation sensor 21 will be described. First, the insert molding die 36 is opened, and when the primary component 31 having the above-described configuration is installed (inserted) in the die, the tip of the clamp pin 37 in the die is inserted into the support hole 27 on one side of the bobbin 22. Insert. Next, the insert mold 36 is closed. At this time, the tip of the clamp pin 37 protruding from the inner surface of the insert mold 36 is attached to the other support provided in advance on the primary component 31 (bobbin 22). The primary component 31 is fitted into the hole 27 and clamped (positioned) so as not to be displaced in the insert mold.

Next, a thermoplastic resin of the same material as that of the bobbin 22 is injected into the cavity space inside the insert molding die 36 in which the mold is closed, and the primary structure is inserted between the primary component 31 and the insert molding die 36. Injection molding (insert molding) of a housing 32 that should surround the component 31 in a watertight manner. After the injection molding of the housing 32, if the mold is opened and the molded product is released, a resin-sealed rotation sensor in which the trace of the clamp pin 37 that is pulled out simultaneously with the release is formed as the trace hole 38 is obtained.

In this embodiment, the housing 3
The thermoplastic resin to be molded into the mold 2 is an insert mold 36.
When injected into the cavity, the thermoplastic molten resin is fed into the cavity space. At this time, the molten resin fed into the cavity space is dissipated by the annular ridges 28 and 35 formed on the primary component 31. Contact with. When the molten resin comes into contact with the annular ridges 28 and 35, particularly the sharp ends of the annular ridges 28 and 35 are melted by the heat of the molten resin, and the molten resin is welded to the annular ridges 28 and 35. I do.

For this reason, the waterproof sealing property between the housing 32 and the support hole 27 or the edge of the hole formed in the primary component 31 is enhanced. That is, in the resin-sealed rotation sensor 21 manufactured by the above-described method, the clamp pin 37 is pulled out at the same time as the mold release, so that the sensor has a trace hole 38 after the clamp pin 37 is pulled out.
The trace hole 38 is exposed as can be seen in the drawing, and a boundary surface between the bobbin 22 and the housing 32 is formed on the inner surface of the trace hole 38. Inside the boundary surface, the annular ridges 28 and 35 and the housing 32 are connected. Is sealed by welding, so that the housing 3
There will be no intrusion of moisture, oil, etc. into the interior of 2,
Therefore, a resin-sealed rotation sensor having excellent waterproof sealing properties can be obtained.

In the insert molding die for insert molding the resin-sealed rotation sensor, a clamp pin 37 for clamping the primary component 31 to be inserted in the mold is integrated with the insert molding die. In addition, the clamp pin 37 is a mechanism that follows the closing and opening operations of the insert molding die, so that the clamp mechanism for the insert part is particularly simplified, thereby providing excellent economy. Insert molds can be provided.

[0031]

As described above, according to the present invention, the clamp mechanism of the insert part in the insert mold can be simplified. As a result, the cost of designing and manufacturing the insert molding die is reduced, and the process management and the like during the insert molding are simplified, and the production economics of the resin-sealed rotation sensor using the insert molding die are greatly improved.

The resin-encapsulated rotation sensor obtained by the present invention is formed in an annular shape surrounding the periphery of a support hole or the like at the joint surface (boundary surface) between the insert-molded primary component and the housing. Since the welded portion for welding the component and the housing is formed, penetration of moisture into the interior of the housing is effectively prevented by the welded portion, and it is possible to provide a resin-sealed rotation sensor excellent in waterproofness. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a resin-sealed rotation sensor according to the present invention.

FIG. 2 is a side external view showing an embodiment of a resin-sealed rotation sensor according to the present invention.

FIG. 3 is a sectional view showing another embodiment of the resin-sealed rotation sensor according to the present invention.

FIG. 4 is a sectional view showing still another embodiment of the resin-sealed rotation sensor according to the present invention.

FIG. 5 is a sectional view showing still another embodiment of the resin-sealed rotation sensor according to the present invention.

FIG. 6 is an enlarged sectional view showing the relationship between a clamp pin, a support hole, and an annular ridge.

FIG. 7 is an enlarged cross-sectional view of another embodiment showing a relationship between a clamp pin, a support hole, and an annular ridge.

FIG. 8 is a sectional view showing the structure of a conventional rotation sensor.

FIG. 9 is an explanatory sectional view at the time of manufacturing a conventional rotation sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 ... Resin-sealed rotation sensor 22 ... Bobbin 23 ... Pole piece 24 ... Magnet 25 ... Spacer 26 ... Pickup coil 27 ... Support hole 28 ... Annular ridge 29 ... Insulating tape 30 ... Terminal bar 31 ... Primary component 32 ... Housing 33 ... female connector part 34 ... mounting bush 35 ... annular ridge 36 ... insert molding die 37 ... clamp pin 38 ... trace hole

Claims (4)

[Claims] 1. A pole piece (23), a magnet (24) and the like are provided inside, and a resin bobbin (22) around which a magnetic change detection coil (26) is wound is provided at an appropriate position on the outside. Forming a bottomed support hole (27) into which the tip of a clamp pin provided in the insert mold is fitted;
On the outer surface of the resin bobbin (22), the support hole (2) is provided.
7) One or more annular ridges (28) surrounding the resin bobbin (22) are integrally formed with the resin bobbin (2).
When the housing (32) surrounding the outer periphery of (2) is insert-molded, the annular ridge (28) melts at the melting temperature of the thermoplastic resin injected into the insert mold to mold the housing. Done, housing (32)
A resin-sealed rotation sensor, which is integrally welded to the rotation sensor. 2. A pole piece (23), a magnet (24) and the like are provided inside, and a resin bobbin (22) for winding a magnetic change detection coil (26) is inserted on the outside. An insert molding die (36) for insert-molding a housing (32) surrounding the outer periphery of the bobbin (22).
A plurality of clamp pins (not shown) for clamping the outer bobbin (22) located in the insert mold (36) at an appropriate position on the cavity surface of the insert mold (36) when the mold is closed. 37) An apparatus for manufacturing a resin-sealed rotation sensor, characterized in that the insert molding die (36) is projected into both male and female molds. 3. A resin product in which a pole piece (23), a magnet (24) and the like are provided inside, and a magnetic change detecting coil (26) is wound around the outside and a terminal bar (30) is attached. A primary component (31) composed of a bobbin (22) and the primary component (31) are supported and stored in an insert molding die (36) with a plurality of clamp pins (37), and then inserted into the insert molding die. A resin-sealed rotation sensor that press-fits a thermoplastic resin between the cavity surface of (36) and the primary component (31) to integrally mold a housing (32) that surrounds the primary component (31) in a watertight manner. In the manufacturing method of (1), a support hole (27) for clamping formed on the outer surface of the resin bobbin and the support hole (2) are provided.
7) A primary component (31) having a resin bobbin (22) integrally formed with one or a plurality of annular ridges (28) surrounding the periphery of the primary component (3) is obtained.
1) Inserting the tip end of the clamp pin (37) in one of the insert molding dies (36) into the support hole (27) and setting it, and then closing the insert molding die (36). At the same time, the clamp pin (3) drilled on the cavity surface in the other mold in the insert mold (36)
7) is inserted into the support hole (27), the primary component is clamped in the insert mold (36), and then the resin bobbin (22) is inserted into the insert mold (37). ) To inject the resin of the same material as above to surround the primary component (31), and to form one or more annular members formed on the outer surface of the resin bobbin (22) by the heat of fusion of the injected resin. The ridges (28) are melted to form a housing (32) that is integrally welded with the annular ridges, and then, after injection molding of the housing (32), the mold is opened and simultaneously with the clamp pin (37). A method of manufacturing a resin-sealed rotation sensor, comprising releasing a clamp of a primary component (31). 4. The sectional shape of the annular ridge (28) is such that the inner wall surface of the annular ridge is inclined and the outer wall surface is formed upright. The resin-sealed rotation sensor according to claim 1.