1. Field of the Invention
The present invention relates to a part mounting clamp used for attaching a wire harness or a part such as a band for tying wire harness to an attaching subject such as a metal panel of an automobile body.
2. Explanation of Related Art
Apart mounting clamp of this kind is generally configured in the following manner. That is, a part mounting clamp includes a support portion which covers a peripheral portion of a mounting hole formed in an attaching subject in a state where the support portion has a part mounting portion, a column which projects from the support portion and is inserted into the mounting hole, and a pair of engaging pieces which extend toward the support portion in a state where the engaging pieces are supported respectively by both sides of a lower end of the column in a cantilever manner, and also, on outer sides of an upper end of which engaging steps are formed, wherein the engaging steps can engage with a peripheral portion of the mounting hole. When the column is inserted into the mounting hole, the pair of engaging pieces are resiliently rocked and deformed inward by slide contact with an inner periphery of the mounting hole, and the engaging step is engaged with the peripheral portion of the mounting hole of the attaching subject, thereby obtaining an attached state wherein the pair of engaging pieces and the support portion sandwich the attaching subject.
As such a part mounting clamp, there are known clamps as disclosed in Japanese Patent Applications Laying-open No. 2001-336509 and No. 2000-270447. In a part mounting clamp disclosed in Japanese Patent Application Laying-open No. 2001-336509, a part mounting portion of a support portion is a holding portion (reference number 3) of cables. The part mounting clamp includes a support portion (reference number 11) having a pair of left and right resiliently supporting pieces (reference number 67), and a pair of engaging pieces (reference number 63) which are supported respectively by left and right sides of a lower end of a column (reference number 61) in a cantilever manner. A peripheral portion of a mounting hole is engaged with an engaging step (reference number 65) by inserting operation into the mounting hole of an attaching subject such as a metal plate (not shown).
In a part mounting clamp disclosed in Japanese Patent Application Laying-open No. 2000-270447, a part mounting portion of a support portion is a band (reference number 1) for tying wire harness. The part mounting clamp includes a support portion (reference number 3) having a pair of left and right pressing pieces (reference number 7), and a pair of engaging pieces (reference number 6b) supported respectively on left and right sides of a lower end of a column (reference number 6) in a cantilever manner. As shown in FIG. 3 of this patent document, a peripheral portion (reference number 4a) of a mounting hole (reference number 4) is engaged with an engaging step (reference number 6d) by inserting operation of an attaching subject (no reference number) such as a metal plate into the mounting hole.
In a part mounting clamp disclosed in any of the above publications, as shown in FIGS. 4 to 6 of Japanese Patent Application Laying-open No. 2000-270447, the pair of engaging pieces are resiliently deformed inward as the column is inserted into the mounting hole, the engaging pieces pass through the mounting hole, and the engaging step is automatically engaged with the peripheral portion of the mounting hole by the outward resilience of the engaging piece. In such a case, the engaging step of the part mounting clamp includes a vertical wall extending along an inner peripheral surface of the mounting hole, and a lateral wall extending along an outer surface of a peripheral portion of the mounting hole. In a mounting state on the mounting hole, a contained angle between the vertical wall and the lateral wall is set to 90° so that it comes in contact with both an inner peripheral surface of the mounting hole and an outer surface of the peripheral portion so as to be stably clamped.
In a conventional part mounting clamp, however, when it is inserted into a mounting hole of a sheet metal panel for an automobile or the like and is attached, it can not be properly attached in some cases. This is because in a case of a sheet metal member, since a mounting hole is also formed by press forming, “a flaggy portion” is generated on an edge of the mounting hole on the press punch entering side, and “a burr” is generated on the opposite side in many cases. That is, as shown in
When a “flaggy portion” exists on the side of the sheet metal member where the engaging piece is engaged, predetermined clamping can be carried out, but a problem occurs when a burr b appears on an angle edge of the mounting hole 3 of the sheet metal member 2 on the side where the engaging piece 8 is engaged as shown in
According to the structure of the part mounting clamp, when the material is synthetic resin or the like, the support portion can be resiliently deformed in the vertical direction to some extent, thereby it is possible to forcibly engage the engaging step 9 with the mounting hole 3 by strongly inserting the engaging step 9 and wrapping the lateral wall 9y below the burr b. However, this operation is slightly deviated from a normal inserting operation of intentionally pushing strongly (operation that requires an unpredictable strong force. Thus, in a practical producing line, the above-described engagement failure often occurs due to insufficient inserting force or the like.
In view of the above circumstances, it is an object of the invention, by revising mainly the structure of the engaging piece, to provide a part mounting clamp in which an engaging piece is strongly and sufficiently engaged with a peripheral portion of a mounting hole so that an excellent attached state can be obtained by a conventional and general inserting operation even under such a condition that a burr exists on a mounting hole of an attaching subject.
The present invention provides a part mounting clamp comprising
a column 7 inserted into a mounting hole 3 formed in an attaching subject 2,
a support portion 6 which is spread sideway from an outer peripheral portion of an upper end of the column 7 and which covers a peripheral portion 2a of the mounting hole 3,
a part mounting portion 5 mounted on the support portion 6 or the column 7,
a pair of engaging pieces 8 and 8 which are extend toward the support portion 6 in a state of being supported respectively on both sides of a tip end of the column 7 in a cantilever manner, and which include tip ends capable of engaging with the peripheral portion 2a of the mounting hole 3, and
engaging steps 9 establishing an attached state in which the pair of engaging pieces 8 and 8 come into slide contact with an inner periphery of the mounting hole 3 by inserting the column 7 into the mounting hole 3, thereby resiliently rocking and deforming the engaging pieces 8 and 8 inward and the attaching subject 2 is sandwiched between the pair of engaging pieces 8 and 8 and the support portion 6, each of the engaging steps 9 including a vertical wall 9t abutting against an inner peripheral surface 3n of the mounting hole 3 in the attaching subject 2, and a lateral wall 9y extending along an outer surface 2A of the peripheral portion 2a of the mounting hole 3 in the attaching subject 2, the engaging steps 9 being formed on outer sides of tip ends of the respective pair of engaging pieces 8 and 8 such that a contained angle of 5° is formed between the lateral wall 9y and the outer surface 2A in an attached state.
According to the present invention, as will be described in detail in an embodiment, it is possible to provide an improved part mounting clamp in which even when an angle edge of the mounting hole on the side where the engaging step is engaged is formed with a burr by the press forming or the like, the engaging step is engaged with the mounting hole and is moved in the predetermined manner by the resilience of the pair of engaging pieces which are forcibly resiliently deformed inwardly so as to pass through the mounting hole together with the inserting operation of the column into the mounting hole, a reliable engaged state can be obtained, it is possible to sufficiently withstand a force in the pulling out direction, it can be held stably. In addition, since the contained angle between the lateral wall of the engaging step and the outer surface of the attaching subject in an attached state is set to 5°, the engaging step can be engaged easily and it is difficult for the engaging step to be pulled out from the mounting hole with excellent balance, in case that there is a burr on the edge of the mounting hole. This shows a high effect that it is easy to mount the engaging step, and a stable attached state can be realized.
In the part mounting clamp of the invention, an angle formed between the inner peripheral surface 3n and the outer surface 2A is 90° or about 90°, and the vertical wall 9t and the lateral wall 9y are set such that an angle therebetween is equal to the angle made by adding 90° or about 90° and the contained angle of 5°.
According to the invention, since the angle formed between the inner peripheral surface of the mounting hole and the outer surface of the attaching subject is 90° or about 90°, the angle formed between the vertical wall and the lateral wall of the engaging step may be set to 90° or about 90° plus 5°.
In the part mounting clamp of the invention, the part mounting portion 5 is an insertion hole formed in the column 7, through which a tying band B for tying wire harness W is inserted.
According to the invention, the part mounting clamp can effectively be used as a harness retaining clamp which ties a wire harness and supports the same on the attaching subject.
Embodiments of a part mounting clamp according to the present invention will be explained with reference to the drawings.
A part mounting clamp according to a first embodiment is constituted as a tying head A having a clamp in a tying fixing tool 1 for tying a wire harness W and clamping the same on an attaching subject 2 in corporation with a tying band B as shown in
As shown in FIGS. 1 to 3, the tying band B has a band member 4 made of synthetic resin having flexibility such as nylon and polypropylene, and one of front and rear surface of the band member 4 is formed with valleys 4a and mountains 4b. The valleys 4a and the mountains 4b are alternately formed in the recessed manner. Retaining portions 4K are continuously formed. Although it is not illustrated in the drawings, a band reel wound around a rotation reel is reeled off and supplied, and the supplied reel is cut into appropriate length and is used as the tying band.
As shown in FIGS. 5 to 7, the tying head A having the clamp includes a support portion 6, a column 7 and a pair of engaging pieces 8 and 8. The support portion 6 covers a peripheral portion of a long circular mounting hole 3 formed in a panel plate 2 (one example of the attaching subject) in a state where the support portion 6 has an insertion hole 5 (one example of the part mounting portion) through which the tying band B is to be inserted. The column 7 projects from the support portion 6 and is inserted into the mounting hole 3. The engaging pieces 8 and 8 extend toward the support portion 6 in a state of being supported respectively on both sides of a lower tip end of the column 7 in a cantilever manner, and the engaging piece 8 is formed at its outer side of its upper end with an engaging step 9 which can be engaged with a peripheral portion 2a of the mounting hole 3. The tying head A having the clamp is made of synthetic resin having flexibility such as nylon and polypropylene. If the column 7 is inserted into the mounting hole 3, the pair of engaging pieces 8 and 8 are resiliently rocked and deformed toward the inside by the sliding motion with respect to the inner peripheral surface 3n (or angle edge) of the mounting hole 3 (see
The support portion 6 is formed into a long and circular reversed cup-like shape as viewed from above, and this shape corresponds to that of the mounting hole 3. The support portion 6 comprises a thick central region 6A which is continuous with the upper end of the column 7, and a skirt portion 6B formed around the column 7. The support portion 6 is formed such that it can be resiliently deformed in the vertical direction (inserting direction into the insertion hole 3) so as to urge and sandwich the peripheral portion 2a of the mounting hole 3 between the pair of left and right engaging pieces (one example of the clamp portion) 8 and 8. As viewed from above, the central region 6A of the support portion 6 is formed thicker than a peripheral portion of the support portion 6.
The column 7 is a cylindrical portion through which the insertion hole 5 is formed vertically. The insertion hole 5 has a substantially rectangular shape as viewed from above (as viewed from below). Both ends 4t and 4t of the band member 4 are inserted into the insertion hole 5 in an opposed state. A pair of second engaging pieces 11 and 11 projects downward and inward in the insertion hole 5. The second engaging pieces 11 and 11 are engaged with valleys 4a of the ends 4t and 4t. The second engaging pieces 11 and 11 are supported in the cantilever manner in a state where they are opposed to each other in the longitudinal direction. The second engaging piece 11 is integrally formed such that it is continuous with the thick column portion 7A at a boundary between the upper thick column portion 7A and the lower thin column portion 7B. The second engaging piece 11 is formed at its inner side with two engaging mountains 11a and engaging valleys 11b.
As shown in
More specifically, as shown in
The first to third steps 9A to 9C are properly used depending upon the thickness of the panel plate 2. When the panel plate 2 is thin, as shown in
Next, a state where a tying-requirement terminal A is mounted on the panel plate 2 will be explained. The mounting hole 3 of the panel plate 2 made of sheet metal is usually integrally formed by press forming. Thus, a peripheral edge of the mounting hole 3 on the press punch entering side is formed with “flaggy portion” which is subjected to angle R processing in many cases, and the peripheral edge of the mounting hole 3 on the press punch discharging side with “burr”. As shown in
If the tying head A having the clamp is inserted into the mounting hole 3 from a terminal end side of the column 7, outer side surfaces 8b of the pair of engaging pieces 8 and 8 which are initially set such that they are slightly opened come into slide contact with the upper angle portion of the mounting hole 3, i.e., the flaggy portion d, and the engaging pieces 8 and 8 are further inserted while they are rocked and deformed inward (toward the column 7). Since the panel plate 2 has the standard thickness, the third step 9C which first comes into contact with the lower angle portion of the mounting hole 3 together with the inserting operation passes as it is, and the second step 9B tries to enter as shown in
According to the engaging step 9 of the present invention, since the contained angle θ between the vertical wall 9t and the lateral wall 9y is set to 95°, the lateral wall 9y of the second step 9B and the lower outer surface 2A of the panel plate 2 are substantially in parallel to each other or form a slight opening angle (such an angle that the lateral wall 9y inclined downward and rightward with respect to the outer surface 2A in
Whereas, according to the conventional part mounting clamp, as shown with a phantom line in
In a state where the second step 9B is engaged with the mounting hole 3 in the intended manner, the vertical wall 9t and the inner peripheral surface 3n of the mounting hole 3 are abutted against each other in a surface-surface contact manner as shown in
For reference, in an attached state when the panel plate 2 is thin, as shown in
A value of the contained angle (contained angle θ between two sides) will be considered. It is preferable that the gap contained angle α is large to some extent in view of easiness of engagement movement of the engaging step 9 to the mounting hole peripheral portion 2a caused when the column 7 is inserted into the mounting hole 3. However, if the gap contained angle α becomes large, component of force for rocking the engaging piece 8 inward by the gap contained angle α is generated when the tensile force in a direction pulling out the wire harness W or the tying head A having the clamp is applied, and there is a problem that the engaging piece 8 is prone to be pulled out from the mounting hole 3. Thus, it is not preferable to increase the gap contained angle α so much. Therefore, it can be said that it is preferable that the gap contained angle α is as small as possible for stably holding as a clamp in a range where the engaging step 9 can be engaged with the mounting hole 3 even if the burr b is generated.
Hence, the height (projecting amount) of the burr b when a mounting hole 3 having general size (about 10 mm) was formed on the panel plate 2 having standard thickness (about 1 mm) by the press forming was checked, and it was found that the height was about 0.2 to 0.3 mm (average value). Thus, in an engagement starting state shown in
As shown in
That is, the tip end inner portion 14 temporarily enters inward more than the outlines of the left and right side walls 12 of the column 7 so that the movable range of rocking movement of the engaging piece 8 is increased inward. As shown with phantom lines in
In such a structure, even when the general and convenient engaging piece 8 is provided at its tip end with the large engaging step 9 having the three steps, i.e., the first to third steps 9A to 9C, it is possible to increase the inward movable rocking range due to the existence of the recessed portion 13 so that it is unnecessary to increase the mounting hole 3 in size. In other words, it is possible to realize the tying head A having the clamp having excellent usage and being capable of attaching in correspondence with various thicknesses of the panel plate 2 and capable of increasing the number of the engaging steps of the engaging step 9 while still using the defined shape and size such as a long circular shape.
As the part mounting clamp A, it is possible to use not only the tying head having the clamp, but also various members such as a tying band having a clamp in which a base portion of the tying band is integrally formed on the tying head having the clamp, and a support metal tool mounting clamp having a nut for bolting a holding metal tool of a high pressure electric wire. It is possible to variably change the attaching subject to a plate forming a body of a vehicle, agricultural machinery, construction machinery and the like, and a frame of the industrial machinery.