JP2008261378A - Screw slip-off prevention structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw slip-off prevention structure in which a component is easily locked to a proper position by adapting to the displacement of a screw locking position caused by machining error and assembling error of the component. <P>SOLUTION: An elongated hole 104 overlapped with a tap hole formed in the component 102 is so drilled in the component 102 as to communicate with the tap hole 103. A male screw 101 extended through the tap hole 103 is movable within the wide range of the elongated hole along the radial direction of the male screw 101. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a screw retaining structure, and more particularly, to a screw retaining structure having a function of fixing a component at an appropriate position in response to a displacement of a screwing position caused by a processing error or assembly error of the component.

  Many conventional screw retaining structures for the purpose of preventing loss of screws for attaching a cover member, etc., by attaching an additional part 100 such as a retaining washer to the male screw 101 as shown in FIG. The male screw 101 is prevented from inadvertently falling off the component 102. However, when such a configuration is applied, if the male screw 101 is pulled too much, an additional component 100 such as a retaining washer made of synthetic resin is used. May fall off from the tip of the male screw 101.

  Further, as shown in FIGS. 5 (a) and 5 (b), the reduced diameter portion 101b is formed on the base side while leaving the effective screw portion 101a at the tip, as shown in FIGS. The male screw 101 is passed through the tap hole 103 of the component 102, and the male screw from the tap hole 103 is utilized using interference between the end 101c near the reduced diameter portion 101b of the effective screw portion 101a and the thread of the tap hole 103. For example, Japanese Patent Application Laid-Open No. H10-228473 is known that prevents the 101 from falling off.

However, this structure has a structure in which the male screw 101 is prevented from falling off by utilizing the interference between the end portion 101c near the reduced diameter portion 101b of the effective screw portion 101a and the thread of the tap hole 103. A large gap cannot be formed between the diameter portion 101b and the tap hole 103, and the movable range in the radial direction of the male screw 101 is reduced. Therefore, a processing error occurs in the engraved position of the tap hole 103. Or the female screw hole of the mounting target component that becomes the receiving side of the male screw 101 due to a processing error or assembly error of the mounting target component on the side to be mounted on the component 102 using the effective screw portion 101a of the male screw 101 In the case where the position is shifted, there is a case where the mounting of the mounting target part may be hindered, and in particular, two locations corresponding to the mounting target part and the part 102 respectively. In a structure in which a female screw hole or a tapped hole 103 is provided in the upper portion and a component to be attached is attached to the component 102, the pitch between the female screw hole side and the tapped hole 103 side is set between the pitches. There is a high possibility that a problem arises in that it becomes difficult to mount the component to be mounted due to the deviation.
In such a case, if the male screw 101 is forcibly screwed into the female screw hole of the part to be attached, the part may be damaged or it may be difficult to remove it again.

Japanese Patent Laid-Open No. 2-199315 (FIG. 6)

  Accordingly, an object of the present invention is to improve the inconveniences of the prior art, to cope with a shift of a screwing position caused by a processing error or an assembly error of a component, and to fix a component easily at an appropriate position. The object is to provide a retaining structure.

In the screw retaining structure according to the present invention, the end portion of the effective screw portion near the reduced diameter portion is formed by passing a male screw having a reduced diameter portion formed on the base side, leaving the effective screw portion at the tip, through the tap hole of the component. And a screw retaining structure that prevents the male screw from falling off the tap hole by utilizing the interference between the tapped hole and the thread of the tap hole.
A long hole with a width equal to or greater than the diameter of the reduced diameter portion of the male screw and less than the maximum diameter of the effective screw portion of the male screw is superposed on the tap hole, and drilled on the part along the diameter direction of the tap hole. It has the structure characterized by having performed.

Since the tapped hole of the part is sized to be screwed with the effective threaded part of the male thread, the interference between the end of the effective threaded part of the male thread near the reduced diameter part and the thread of the tapped hole is used as before. Thus, it is possible to prevent the male screw from dropping from the tap hole.
The tap hole is further drilled in contact with the tap hole so as to overlap with the tap hole, so that the reduced diameter portion of the male screw that penetrates the tap hole is moved along the long hole. Compared to the case where the male screw is passed through a simple tap hole, the male screw can be moved in a wider range along the radial direction of the male screw. The mounting target part that becomes the receiving side of the male screw due to a processing error or assembly error of the mounting target part on the side that is attached to the part by using the effective threaded part of the male screw, if a processing error occurs in the position Even if the position of the female screw hole is misaligned, align the effective screw part of the male screw with the position of the female screw hole of the mounting target part, and securely screw the male screw and female screw hole together. The component to be attached can be fixed to the component.
The width of the long hole provided to allow the movement of the male screw is equal to or greater than the diameter of the reduced diameter portion of the male screw and is less than the maximum diameter of the effective screw portion of the male screw. Both sides and the end near the reduced diameter portion of the effective thread of the male thread interfere with each other to prevent the male thread from falling out of the elongated hole, and without impairing the function of preventing the male thread from falling off. The male screw can be moved in a wide range along the radial direction.

  The elongated hole may be drilled so that one end of the elongated hole projects to one side of the tap hole, or the elongated hole is drilled so that both ends of the elongated hole project to both sides of the tap hole. Also good.

  If the slot is drilled so that one end of the slot protrudes to one side of the tap hole, the slot is drilled so that the center of the slot matches the screwing position on the part. In addition, when a long hole is drilled so that both ends of the long hole protrude on both sides of the hole, the tap hole should be cut so that the center of the tap hole matches the screwing position on the part. This makes it possible to move the male screw in either direction around the design standard for the screwing position on the part, and the misalignment of the female screw hole on the part to be mounted that is the receiving side of the male screw or the tapped hole itself It is desirable to adopt a configuration that can cope with the positional deviation.

In the screw retaining structure according to the present invention, a long hole that overlaps with a tapped hole engraved in a part is formed in contact with the tapped hole, so that the male thread that penetrates the tapped hole is arranged in the radial direction of the male thread. It is possible to move along a wide range along the line, and when there is a processing error in the engraved position of the tapped hole, or processing error or assembly of the part to be mounted on the side that is attached to the part using a male screw Even if the position of the female screw hole of the mounting target part on the receiving side of the male screw is shifted due to an error, etc., align the effective screw part of the male screw with the position of the female screw hole of the mounting target part. The component to be attached can be fixed to the component by securely screwing the male screw and the female screw hole.
In particular, since the width of the long hole provided to allow the movement of the male screw is equal to or larger than the diameter of the reduced diameter portion of the male screw and less than the maximum diameter of the effective screw portion of the male screw, There is an advantage that the male screw can be moved in a wide range without impairing the function of preventing the screw from falling off.

  Next, the best mode for carrying out the present invention will be specifically described with reference to the drawings.

  FIG. 1A is a cross-sectional view generally showing a screw retaining structure 1 according to an embodiment to which the present invention is applied, and FIG. 1B is a part of the screw retaining structure 1 according to the embodiment. FIG. 1C is an enlarged view showing the peripheral structure of the tap hole 103 on the component 102 side through which the male screw 101 passes.

  As shown in FIGS. 1 (a) and 1 (b), the male screw 101 is formed with a reduced diameter portion 101b equal to or smaller than the minimum diameter of the effective screw portion 101a on the base side, leaving the effective screw portion 101a at the tip. Thus, it has the same configuration as the conventional example shown in FIGS. 5 (a) and 5 (b).

  As shown in FIG. 1 (c), a tapped hole 103 that fits the effective threaded portion 101 a of the male screw 101 is engraved in the component 102 through which the male screw 101 passes, and the tapped hole 103 overlaps with the tapped hole 103. Thus, a long hole 104 having a lateral width W equal to or larger than the diameter D1 of the reduced diameter portion 101b of the male screw 101 and less than the maximum diameter D2 of the effective screw portion 101a is formed on the component 102 along the diameter direction of the tap hole 103. Has been drilled.

  FIG. 1C shows an example in which the long hole 104 is formed so that one end 104a of the long hole 104 protrudes to one side of the tap hole 103. However, as shown in FIG. The long hole 104 may be formed so that both end portions 104 a and 104 b of the hole 104 protrude on both sides of the tap hole 103.

When the one end 104 a of the elongated hole 104 protrudes to one side of the tap hole 103 as shown in FIG. 1C, the elongated hole 104 is elongated so that the center Gh of the elongated hole 104 matches the screwing position on the component 102. In the case where the hole 104 is to be drilled and the both end portions 104a and 104b of the elongated hole 104 protrude to both sides of the tap hole 103 as shown in FIG. 1 (d), the center Gt of the tap hole 103 is the part. It is assumed that the tap hole 103 is engraved so as to match the screwing position on the 102.
That is, in any case, as a result, it is desirable to match the center of the tap hole 103 with the designed screwing position.

  When attaching the male screw 101 to the component 102, the effective screw portion 101a of the male screw 101 is screwed into the tap hole 103 of the component 102 and rotated clockwise (in the case of a positive screw), so that the entire effective screw portion 101a is obtained. Is completely projected from the tap hole 103.

  Since the maximum diameter D2 (diameter of the thread portion) of the effective screw portion 101a is larger than the minimum inner diameter d1 (inner diameter of the thread portion) of the tap hole 103, the end portion 101c of the effective screw portion 101a near the reduced diameter portion 101b The thread of the tap hole 103 interferes and the male screw 101 is prevented from falling off from the tap hole 103. This is the same as the conventional example shown in FIGS. 5 (a) and 5 (b).

  In the present embodiment, in particular, the elongated hole 104 is formed so as to overlap with the tap hole 103 so as to communicate with the tap hole 103 on the component 102, so that the male screw 101 penetrating the tap hole 103 is formed. The reduced diameter portion 101b can be moved in the radial direction of the male screw 101 along the elongated hole 104, and the male screw 101 is passed through a simple tap hole 103 as shown in FIGS. ), The male screw 101 can be moved in a wider range along the radial direction of the male screw 101.

  That is, in the conventional example of FIGS. 5A and 5B in which the male screw 101 is passed through the simple tap hole 103, the diameter of the reduced diameter portion 101b of the male screw 101 is D1, and the minimum inner diameter of the tap hole 103 is When d1 is d1, the range in which the male screw 101 can move along the radial direction is [d1-D1] as a whole, and the distribution amount to one side is as shown in FIG. D1) / 2].

  On the other hand, in the case of the configuration of the present embodiment in which the one end 104a of the elongated hole 104 protrudes to one side of the tap hole 103 as shown in FIG. Since the overall length L of the entire long hole formed in combination with the long hole 104 is larger than the minimum inner diameter d1 of the tap hole 103, the range in which the male screw 101 can move along the radial direction as a whole is [L-D1. In addition, as shown in FIG. 2 (b), the distribution amount to one side is [(L-D1) / 2], and the male screw 101 is moved in a wider range along the radial direction of the male screw 101. It becomes possible to make it. Similarly, even when the elongated hole 104 is formed so that both end portions 104a and 104b of the elongated hole 104 protrude on both sides of the tap hole 103 as shown in FIG. Is L (L> d1), the range in which the male screw 101 can move along the radial direction is as a whole [L-D1], and the distribution amount to one side is as shown in FIG. [(L-D1) / 2], and the male screw 101 can be moved in a wider range along the radial direction of the male screw 101.

  Moreover, the width W of the long hole 104 provided to allow the movement of the male screw 101 is equal to or larger than the diameter D1 of the reduced diameter portion 101b of the male screw 101 and less than the maximum diameter D2 of the effective screw portion 101a. For example, since it is the same size as the minimum inner diameter d1 (inner diameter of the thread portion) of the tap hole 103, both end portions of the long hole 104 and the end portions of the effective screw portion 101a of the male screw 101 near the reduced diameter portion 101b. 101c interferes with the male screw 101 from the elongated hole 104 and prevents the male screw 101 from falling out of the component 102, and the function of preventing the male screw 101 from falling off the component 102 is not impaired. The male screw 101 can be moved in a wide range.

  An example in which the mounting target component 2 is mounted on the component 102 using the screw retaining structure 1 of the embodiment will be described with reference to FIG.

  In the example shown in FIG. 3, the male screw 101 is attached to two parts 102 by applying the screw retaining structure 1 described above, and protrudes from the part 102 side on the part 2 side to be attached. Two female screw holes 105, 105 that fit the effective screw portions 101a, 101a of the two male screws 101, 101 are formed.

  In design, the arrangement pitch between the male screws 101 and 101 and the arrangement pitch between the female screw holes 105 and 105 are both set to the same value, for example, P. However, due to processing errors and assembly errors, the female screw holes In some cases, the arrangement pitch between 105 and 105 and the arrangement pitch between the male screws 101 and 101 may be out of order. Here, the actual arrangement pitch between the male screws 101 and 101 is indicated by P1, and the actual arrangement pitch between the female screw holes 105 and 105 is indicated by P2.

  Of these, the displacement [P-P1] of the arrangement pitch between the male screws 101 and 101 is simply caused by the positioning accuracy of the machine tool and is not generally large, but the two pressed parts 2a , 2b is attached to the mounting target part 2 with a relatively large arrangement pitch due to the dimensional error of each part 2a, 2b, the effect of springback during bending, the assembly error when fixing both parts, and the like. It is conceivable that a deviation [P-P2] occurs.

  Here, the final problem in attaching the attachment target component 2 to the component 102 is that the actual arrangement pitch P1 between the male screws 101 and 101 and the actual arrangement pitch between the female screw holes 105 and 105 are the same. Is a deviation [P1-P2] corresponding to a deviation between P2.

  In the embodiment shown in FIG. 3, the long holes 104, 104 are arranged so that the two long holes 104, 104 are aligned in the longitudinal direction along the linear direction connecting the design mounting positions of the male screws 101, 101 on the component 102. 104 is formed in the part 102, and when the one end 104a of the elongated hole 104 protrudes to one side of the tap hole 103 as shown in FIG. 1C, the center Gh of the elongated hole 104 is A long hole 104 is formed so as to match a design screwing position on the part 102, and both end portions 104a and 104b of the long hole 104 project to both sides of the tap hole 103 as shown in FIG. In the case where the configuration is such that the tap hole 103 is engraved so that the center Gt of the tap hole 103 matches the screwing position on the component 102, each of the male screws 101, 101 is shown in FIG. Neutral position indicated In other words, it is possible to move independently from the design mounting position in the range of ± [(L−D1) / 2] in the forward and reverse directions of the double-ended arrow A in FIG. The deviation [P1-P2] between the actual pitch P1 between the screws 101, 101 and the actual pitch P2 between the female screw holes 105, 105 is within the range of ± | L-D1 |. For example, the effective screw portions 101a and 101a of the male screws 101 and 101 are securely aligned with the positions of the female screw holes 105 and 105 of the attachment target component 2, and the male screws 101 and 101 are screwed into the female screw holes 105 and 105. Thus, the attachment target component 2 can be fixed to the component 102.

  Since the range of movement of the male screw 101 in the radial direction is increased, it is not limited to misalignment due to processing errors or assembly errors. For example, warping due to secular change such as for fixing a panel cover of a large housing It is possible to cope with a large pitch deviation between the fixed parts due to bending or plastic deformation, etc., and it is also useful as a screw retaining structure to prevent the screws from falling off or losing from the removable cover. .

  Since the amount of movement of the male screw 101 in the radial direction can be increased only in the direction along the longitudinal direction of the long hole 104, the direction of the long hole 104 is, for example, as illustrated in FIG. It is desirable to match the direction in which the longitudinal direction is substantially the same as the linear direction connecting the designed mounting positions of the male screws 101 on the component 102, in a broader sense, in the direction in which processing errors and assembly errors are accumulated.

1A and 1B are views showing a screw retaining structure according to an embodiment to which the present invention is applied. FIG. 1A is a cross-sectional view generally showing the screw retaining structure of the embodiment, and FIG. Sectional drawing which expanded and showed a part of screw retaining structure of the embodiment, FIG.1 (c) is an enlarged view which showed the periphery structure of the tap hole which a male screw penetrates, FIG.1 (d) is male It is the enlarged view which showed the other example about the surrounding structure of the tap hole which a screw penetrates. FIG. 2A is an operation principle diagram showing a comparison between a screw retaining structure of the embodiment and a conventional screw retaining structure, and FIG. 2A shows a male when a conventional screw retaining structure is applied. The movement limit of the screw is shown, and FIG. 2B shows the movement limit of the male screw when the screw retaining structure of the embodiment is applied. It is the side view shown about the example which attached the attachment object part to the part with two male screws using the screw retaining structure of the embodiment. It is an operation principle diagram showing a conventional screw retaining structure in which a male screw is prevented from falling off using a retaining washer. FIG. 5A is an operation principle diagram showing a conventional screw retaining structure in which a reduced diameter portion is formed on the male screw to prevent the male screw from falling off, and FIG. FIG. 5B is a partially enlarged view.

Explanation of symbols

1 Screw retaining structure 2 Parts 2a and 2b to be installed Pressed parts 100 Additional parts (Retaining washer)
101 Male screw 101a Effective screw part 101b Reduced diameter part 101c End part 102 near the reduced diameter part Part 103 Tap hole 104 Long hole 104a One end part 104b of the long hole Other end part 105 of the long hole Female screw hole D1 Reduced diameter of the male screw Diameter of part D2 Maximum diameter of effective thread of male thread d1 Minimum inner diameter of tap hole W Horizontal width of long hole L Total length of long hole Gh Center of long hole Gt Center of tap hole P Common between male screw and female screw hole Design arrangement pitch P1 Actual arrangement pitch P2 between male screws Actual arrangement pitch between female screw holes

Claims (5)

By passing a male screw having a reduced diameter portion on the base side while leaving an effective screw portion at the tip through the tap hole of the component, the end portion near the reduced diameter portion of the effective screw portion and the thread of the tap hole A screw retaining structure that prevents the male screw from falling out of the tap hole using interference,
A long hole having a lateral width equal to or greater than the diameter of the reduced diameter portion of the male screw and less than the maximum diameter of the effective screw portion of the male screw is superposed on the tap hole, and the component is formed along the diameter direction of the tap hole. Screw retaining structure characterized by being drilled on top.   The screw retaining structure according to claim 1, wherein one end of the elongated hole protrudes to one side of the tap hole.   3. The screw retaining structure according to claim 2, wherein the elongated hole is formed so that a center of the elongated hole coincides with a screwing position on the component.   2. The screw retaining structure according to claim 1, wherein both end portions of the elongated hole protrude on both sides of the tap hole.   5. The screw retaining structure according to claim 4, wherein the tap hole is formed so that a center of the tap hole coincides with a screwing position on the component.

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