JPH028574Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a mandrel mounting structure for easily attaching and removing the mandrel in a pipe expansion device that expands a pipe by press-fitting the mandrel into the pipe. .

(Prior Art) Conventionally, as a tube expansion means using this type of mandrel, for example, the technique disclosed in Japanese Patent Application Laid-Open No. 1983-1981, which was developed by the applicant of the present invention,
-There is one described in Publication No. 174234.

In this conventional method, as shown in FIG. 5, a mandrel 1a is inserted into a through hole 6 formed in a mounting plate 4a that is raised and lowered by a cylinder or the like, and supported.
During tube expansion by lowering the mandrel 1a, the upper part of the mandrel 1a can be pressed by a mandrel pressing attachment 18a arranged on the upper surface of the mounting plate 4a.

Here, in the conventional mounting of the mandrel 1a, a hanging member 20 having a larger diameter than the through hole 6 is removed from the upper part of the mandrel 1a which is inserted into the through hole 6 and protrudes above the mounting plate 4a. It was fastened in place.

(Problem to be Solved by the Invention) Therefore, with the conventional means of simply fixing the hooking member 20 to the upper part of the mandrel 1a, when the mandrel 1a is attached and detached from the mounting plate 4a, the hooking member 20 It is necessary to remove them one by one from the mandrel 1a.

However, in most cases, the mandrel 1a of this type of tube expansion device is very long in accordance with the dimensions of the tube to be expanded, and the mounting plate 4a is actually located at a high location above the tube expansion device. be. Therefore,
When replacing the mandrel 1a, it is necessary to go up to a high place in the tube expansion device and attach/detach the locking member 20, which is very complicated and takes a long time.

Therefore, the purpose of the present invention is to eliminate the need for workers to climb up and down the tube expansion equipment when attaching and detaching the mandrel, and to make it possible to attach and detach the mandrel with ease. do.

(Means for Solving the Problems) The present invention attempts to solve the above-mentioned conventional problems by devising a mandrel mounting structure so that the mandrel can be attached and detached from the lower side of the mounting plate.

That is, in the present invention, on the upper surface side of the mounting plate 4, which can freely reciprocate along the vertical direction of the tube expansion device, a pipe is inserted into the through hole 6 of the mounting plate 4 from the lower side and protrudes above the mounting plate 4. This is a mandrel mounting structure in a tube expansion device, which is provided with a holder 8 for holding the mandrel, which is provided with a hole 10 into which the upper part of the mandrel 1 is inserted.
In this example, a plurality of holder bodies 9, 9a each having a recess 50 for forming a hole 10 on the inner surface are connected to an elastic member 11.
The mandrel 1, which is elastically biased in the direction of approaching each other by the elastic force of the upper part of the mandrel 1 and has a concave or convex step 3, is fitted into and removed from the hole 10 of the upper part of the mandrel 1. The inner diameter of the hole 10 is set to be changeable to increase or decrease so that the mandrel 1 fitted into the portion 10 can be freely rotated, and the hole 10 of the holder 8
A part of the inner surface of the mandrel 1 is provided with a groove to prevent the mandrel 1 from slipping out only when the upper end of the mandrel 1 is relatively rotated within the hole 10 of the holder 8 and faces the stepped part 3 of the mandrel 1. This is a mandrel mounting structure in a pipe expanding device, which is provided with a convex or concave engaging portion 14 that engages with the stepped portion 3.

(Function) In the mandrel mounting structure characterized by the above configuration, the inner diameter of the hole 10 of the holder 8 provided on the upper surface side of the mounting plate 4 can be increased or decreased. In this state, if the mandrel 1 is rotated relative to the holder 8 and the stepped part 3 is opposed to and engaged with the engaging part 11 on the inner surface of the holder 8, the mandrel can be fitted. 1 can be latched onto the holder 8 in a manner that prevents it from coming off. As a result, the mandrel 1 is attached to the mounting plate 4. Since the holder 8 is biased by the elastic force of the elastic member 11 so that the inner diameter of the hole 10 is reduced, the engagement state between the engaging portion 14 and the stepped portion 3 is maintained appropriately, and no malfunction occurs. There is no risk that the engaged state between the two 1 and 8 will be accidentally released.

In addition, when removing the mandrel 1, it is sufficient to rotate the mandrel 1 relative to the holder 8 to displace the stepped part 3 from the position of the engaging part 14. In this state, the mandrel 1 can be simply pulled downward. The mandrel 1 can be removed from the holder 8 and the mounting plate 4.

Therefore, the operation of attaching and detaching the mandrel 1 can be performed only by inserting and removing the mandrel 1 into the hole 10 of the holder 8 and rotating it. The worker can hold the lower part of the mandrel 1 at a low place without having to climb up to a high place.

(Example) Examples of the present invention will be described below.

In Fig. 1, reference numeral 1 denotes a substantially cylindrical rod-shaped mandrel for press-fitting into the pipe to be expanded, and an eccentric small-diameter part 2 is formed in the upper part of the mandrel, and a concave stepped part 3 is formed on the side surface of the mandrel. It is located in the department. Reference numeral 4 denotes a mounting plate provided at the bottom of the vertically movable pushing body 5 of the tube expansion device, and a small diameter through hole 6 for inserting the mandrel 1 is bored in the lower surface side of the mounting plate. A large diameter recess 7 is connected to the upper side.

Reference numeral 8 denotes a holder housed in the recess 7 of the mounting plate 4, and the two holder bodies 9 and 9a, each having a semicircular cross section and an arcuate recess 50 formed therein as shown in FIG. 2, can expand and contract between them. They are arranged facing each other to form a hole 10, and the overall shape is a half-cylindrical shape. 11 are two holder bodies 9,
A ring-shaped coil spring (corresponding to the elastic member 11 of the present invention) externally fitted on the holder body 9a constantly biases each holder body 9, 9a to bring the pair of holder bodies 9, 9a closer to each other. be. 12,
Reference numeral 12 denotes guide shafts that are fitted into holes 13 formed in the oppositely facing surfaces of each holder body 9, 9a, and guide shafts that guide each holder body 9, 9a when the holders 8 approach or move away from each other. It is meant to guide you.

Reference numeral 14 denotes an engaging portion which is protruded into a curved inner surface 15 of one of the holder main bodies 9 in a substantially arcuate planar shape, and is capable of engaging with the stepped portion 3 of the mandrel 1 when the engaging portion 14 comes into opposing contact with the stepped portion 3. Dimensions are set.

Reference numeral 16 denotes a downwardly expanding tapered surface formed on the inner periphery of the lower surface of the holder body 9, 9a. Reference numeral 17 indicates a series of grooves carved in the upper surface of the holder bodies 9, 9a. An attachment 18 is detachably provided in a space 21 formed between the upper surface side of the mounting plate 4 and the lower surface of the pushing body 5, and the attachment 18 has the recess facing the upper surface of the holder 8 on its lower surface. A protrusion 19 of a size that can fit into the groove 17 is provided in a protruding manner. Further, a through hole 22 is formed at the position of the convex portion 19, and a plug 23 is screwed into the upper portion of the through hole 22.

The present embodiment has the above configuration, and next, an example of its use and operation will be explained.

First, in order to attach the mandrel 1 to the mounting plate 4, the holder 8 is housed in the recess 7 of the mounting plate 4 as shown in FIG. 6 from below and forcefully fit into the hole 10 of the holder 8. Since a downwardly expanding tapered surface 16 is formed at the lower part of the hole 10 of the holder 8, even if the holder 8 is slightly displaced from the through hole 6, the insertion operation can be performed accurately.

Here, the minimum value l of the inner surface position where the engaging portion 14 of the holder 8 is provided is smaller than the upper diameter la of the mandrel 1, but since the holder 8 is expandable and retractable, the mandrel 1 is The holder 8 is expanded against the elastic force, and the upper part of the mandrel 1 is fitted into the holder 8.

Thereafter, in the fitted state, the mandrel 1 is made to face the holder 8 and rotated appropriately so that the stepped part 3 of the mandrel 1 faces the engaging part 14 of the holder 8. Then, as shown in FIG. 1, both 3 and 14 are engaged with each other, and the mandrel 1 is prevented from being removed from the holder 8. This completes the attachment of the mandrel 1 to the mounting plate 4. Further, since the holder 8 is closed by the elastic force of the coil spring 11, the engaged state between the stepped portion 3 and the engaging portion 14 is reliably maintained.

In the mounted state of the mandrel 1 shown in FIG. 1, since the mandrel 1 and the holder 8 are prevented from rising by the attachment 18, the mandrel 1 is pushed downward by lowering the pushing body 5, and the mandrel 1 is pushed downward. This makes it possible to appropriately press-fit and expand the tube placed below it.

Next, when removing the mandrel 1 from the mounting plate 4, first grasp the lower or middle part of the mandrel 1 and lift it slightly, and then bring the holder 8 on the upper part of the mandrel 1 into contact with the lower surface of the attachment 18. Then, as shown in FIG. 4, the concave groove 17 on the upper surface of the holder 8 is fitted into the convex portion 19 of the attachment 18. If the mandrel 1 is rotated in this fitted state, the mandrel 1 can be rotated relative to the holder 8 which is stopped from rotating by engagement with the convex portion 19 of the attachment 18. By this rotation of the mandrel 1, the stepped portion 3 is placed in a position not facing the engaging portion 14 of the holder 8, and the engagement between the two is released. Therefore, if the mandrel 1 is then pulled downward, the mandrel 1 can be easily removed from the holder 8 and can be easily removed.

In the above embodiment, the mandrel 1 was provided with the eccentric small diameter portion 2 and the concave stepped portion 3, and the holder 8 was provided with the engaging portion 24, which was a convex portion in the shape of a plane arch. The specific shapes and forming means of the step portion 3 and the engaging portion 14 are by no means limited to these. For example, the stepped portion of the mandrel 1 may be formed in a convex shape, and the engaging portion of the holder 8 may be formed in a concave shape.

Furthermore, in the above embodiment, the holder 8 was composed of two halved cylindrical holder bodies 9 and 9a.
The specific shape, number, etc. of the holder body are never specified.

Further, in the above embodiment, a protrusion 19 that can be engaged with and detached from the groove 17 of the holder 8 is provided on the lower surface of the attachment 18 disposed above the holder 8, so that the holder 8 is prevented from rotating. However, such means are not an essential requirement of the present invention. In the present invention, there is no problem even if the holder 8 is previously provided in a rotationally prevented state with respect to the mounting plate 4.

In addition, in the present invention, the design of the specific configuration of each part such as the mounting plate 4 can be changed arbitrarily within the scope of the present invention. The elastic member 11 is by no means specified as a coil spring.

(Effects of the invention) As described above, the present invention provides a holder on the top side of the mounting plate of the tube expansion device, which allows the inner diameter of the hole to be changed freely. After inserting the upper part, the step part of the mandrel is made to face the engaging part on the inner surface of the holder, so that the mandrel can be engaged with the holder and attached to the mounting plate. This can be done only by inserting and removing the mandrel into and out of the mounting plate, and by rotating the mandrel, and all of these operations can be performed from a position below the mounting plate.

Therefore, it is no longer necessary for the operator to climb up to a high place with a mounting plate and attach/detach a separate fixing member to the top of the mandrel each time the mandrel is attached/detached, as was the case in the past. The replacement work can be done easily and quickly, and the work efficiency can be improved, which is a special effect.

Further, in the present invention, when the stepped part of the mandrel is engaged with the engaging part of the holder, the holder can be biased by the elastic force of the elastic member so that the inner diameter of the holder is reduced. Another advantage is that the state of engagement between the holder engaging portion and the stepped portion of the mandrel can be maintained reliably, and the state of attachment of the mandrel can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing an embodiment of the mandrel mounting structure according to the present invention. FIG. 2 shows an example of the holder, in which A is a plan view of the holder in a reduced state, and B is a plan view of the holder in an expanded state. FIG. 3 and FIG. 4 are sectional views of main parts showing the state of attachment and detachment of the mandrel. FIG. 5 is a sectional view of main parts showing a conventional example. DESCRIPTION OF SYMBOLS 1... Mandrel, 3... Step part, 4... Mounting plate, 6... Through hole, 8... Holder, 10... Hole, 9, 9a... Holder body, 11... Elastic member, 14... ...Engagement portion, 50...Recessed portion.

Claims (1)

[Scope of utility model registration request] The upper part of the mandrel 1, which is inserted into the through hole 6 of the mounting plate 4 from the lower side and protrudes above the mounting plate 4, is fitted onto the upper surface side of the mounting plate 4, which can freely reciprocate along the vertical direction of the tube expansion device. This is a mandrel mounting structure in a tube expansion device, which is provided with a holder 8 for holding the mandrel, which is provided with a hole 10 for forming the hole 10, and the holder 8 has a recess 50 for forming the hole 10 on the inner side. A mandrel 1 in which a plurality of holder bodies 9, 9a provided in the mandrel are elastically biased in a direction toward each other by the elastic force of an elastic member 11 to form a concave or convex stepped portion 3. The inner diameter of the hole 10 is set to be changeable to increase or decrease so that the upper part of the mandrel 1 can be inserted into and removed from the hole 10 and the mandrel 1 fitted into the hole 10 can be rotated freely. A portion of the inner surface of the portion 10 is provided to prevent the mandrel 1 from slipping out only when the upper end of the mandrel 1 is relatively rotated within the hole 10 of the holder 8 and faces the stepped portion 3 of the mandrel 1. A mounting structure for a mandrel in a tube expanding device, characterized in that a convex or concave engaging portion 14 is provided to engage with the stepped portion 3.