JPH01154842A - Metal plate made poly-v pulley and its manufacturing method and device - Google Patents

Abstract

PURPOSE:To improve an accuracy by forming numerous unevennesses at the back face inner diameter part of the V-groove part on the outer peripheral face of a metal plate made poly V-pulley therein. CONSTITUTION:A poly V-pulley is made of one plate and its cylindrical part has numerous V-grooves 2 and at both ends of this cylindrical part, the flange part 4 having the outer diameter larger than that of the V-crest 3 between the V-grooves 2 and the flange part 5 superposed by two sheets exist. The center part from the flange part 5 is a disk, having a center hole 6, Numerous unevennesses are provided on the inner diameter part of the back side of the V-groove 2 and this unevenness is composed of the recessed part 7 and projecting part 8 running in parallel to the axial line A direction. The diameter increase of the center part is thus reduced with the rolling of the case of form rolling being constrained and the angular accuracy is improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet metal bow IJy pulley formed into a predetermined shape by plastic working of sheet metal material, and a method and apparatus for manufacturing the same.

Currently, poly-V pulleys are mainly manufactured by cutting, but for those used in large quantities, a method of manufacturing by plastic working of sheet metal material is being adopted.

Therefore, although the manufacturing technology of poly-V pulleys by plastic working of sheet metal materials has progressed considerably, there still remains the drawback of (1) poor precision in the groove portion.

The first object of the present invention is to provide a poly V pulley made of sheet metal that eliminates this drawback, and in order to achieve this object, the poly V pulley according to the present invention has a It is characterized by the formation of unevenness.

Further, according to the present invention, there is provided a method and apparatus for manufacturing a poly-V pulley by plastic working, which can minimize the number of processing steps compared to conventional methods. To summarize the invention in this regard, first, a cylinder with a bottom is made by a currently very common method of collecting. Next, as an important point of this invention, the cylindrical portion of the bottomed cylinder is partially thickened. Next, holes such as a center hole and bolt holes for attachment are drilled in the cylinder with a bottom whose thickness has been increased. Finally, the grooves are rolled, which is also an important point of this invention.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The embodiment of the pulley of the present invention, shown in cross-section in FIG. There is a flange portion having an outer diameter larger than the outer diameter of the V-shaped ridge 3 between the legs and a flange portion S which is a single layer. The center part from the flange part S is a disk and has a center hole 6. In practice, a disc is often provided with a plurality of bolt holes on its outer periphery, and also with thinning holes for weight reduction. What has been explained above is generally well known, and when it is made from a single plate, it has no choice but to have such a shape.

Therefore, the gist of this invention lies not in what is described in iiJ, but in the provision of a large number of irregularities on the inner diameter portion of the back side of the groove. As shown in the front view of the poly-V pulley in FIG. 2, this unevenness consists of a concave portion 7 and a convex portion g running parallel to the direction of the axis A.

This unevenness has nothing to do with (1) the function of the pulley, but by forming this unevenness, (2) the accuracy of the groove, which is a functional part, is improved. Details regarding this point will be described later.

Next, a method for processing this will be explained with reference to FIG. 3, FIG. 3, FIG. S, and FIG. 6.

The drawing process shown in FIG. 3 is currently widely performed, so there is no need to explain the process, but in this invention, the outer diameter of the cylindrical portion of the material l is
It is almost equal to the outer diameter of

The second figure shows a shape in which a portion of the cylindrical portion is thickened, and reference numeral IO indicates the thickened portion. This thickening process is difficult;
With current technology, this is possible by increasing the number of processing steps, but
This would result in high costs, so it is rarely used productively. The present invention focuses on this point and provides a specific method for increasing the thickness in several steps.

Figure 5 shows the drilling process, in which center holes, bolt holes, etc. are drilled. This also seems to need no explanation.

FIG. 16 shows the rolling process which is an important item of this invention. One of its features is that the material has a diameter almost equal to that of the 7-launch portion S, while reducing the material to the diameter of the groove.
By performing iM transmission, the entire process is simplified. Another feature is that (2) unevenness is formed on the inner diameter portion of the back surface of the V-groove during groove rolling to improve the accuracy of (2) the groove.

As described above, the important parts of this invention can be summarized into the following three parts. 7 is the shape of the poly V pulley itself, which improves the accuracy of the groove by forming irregularities on the inner diameter of the back side of the R'fi.Next, we have a very annualized manufacturing method and this. It is a processing technology to materialize, and the main points of this technology are:
This process consists of the thickening process and the rolling process.

Since the present invention has been explained in detail above, the specific processing technology will be explained in detail below, but as mentioned above, what needs to be explained is the thickening process shown in Fig. 7 and the rolling process shown in Fig. 6. It's just the process.

First, the thickness increasing method in the thickness increasing process shown in FIG. 7 will be described.

FIG. 7 shows the processing principle of this thickening method.

The symbol / indicates the material that has been subjected to the drawing process shown in FIG. The male mold // and the upper mold l- can move downward while holding the bottom part of the material l, /6. However, since the lower end of the material 1 is in contact with the stepped portion 1 of the fixed mold /9, it does not move. Therefore, when the male mold 1/ and the upper mold 1 move downward, 1. The length of the cylindrical portion of the material / becomes shorter.

The broken line /'4a indicates that the bottom part /6 has changed position. However, above the cylindrical part of the cylindrical part, there is a female mold /3, and below it there is a split mold /S, which can increase the diameter.
The excess meat due to the shortening of the length of the cylindrical part of the material protrudes from the part of the split mold IS that can increase the diameter. What is important here is that a constant pressure is maintained toward the center of the split mold 15. If this pressure is weak,
Both the inner and outer diameters of the cylindrical portion swell, resulting in bulge processing rather than thickening. Therefore, in order to increase the thickness, it is necessary to accurately control the magnitude of the pressure.

The principle of the above-mentioned thickening process is disclosed in Patent Application No. G90'1A of 1939, filed on September 3, 1939, entitled "Method and Apparatus for Increasing Thickness of Thin-Walled Cylindrical Body" It is the same as what has been done.

Therefore, a specific device in which this poly-V pulley pressure is applied will be described below with reference to FIGS. 5, 9, and 70. Figure 5 is a cross-sectional view of the mold for increasing the thickness, and the left side of the center line B shows the state before the thickening process begins. The right side shows the state at the end of the thickening process. Further to the right, the hydraulic control of the split mold is indicated using the symbol of a hydraulic system. Figure Vq shows a cross-section of the split mold 15 and its surroundings without hatching, and Figure 70 shows a partially enlarged view.

The operation of these functions will be explained step by step.
An explanation of the basic structure of molds, etc., which current sheet metal processing engineers can understand at a glance, will be omitted.

At the beginning of the thickening process, the blank / is inserted into the top of the male mold l/. At this time, the ram of the press is at the top dead center, the mold is wide open, and the male die l/ is at the
Insertion is easy as it is lifted into place by the g. The ram is then lowered and the bottom 16 of the blank 1 is wedged between the knockout 1- and the male die //.

At this time, the female die 13 fits into the outer diameter of the material and restrains that part. When the ram further descends, the lower surface of the female mold/3 comes into contact with the upper surface of the split 9 mold 15 and stops. At this time, the end of the material / is approaching the step /7 of the fixed mold /l. When the ram further descends, the i cloud knockout/- descends while compressing the elastic body/9 located at the top of the female mold/3, and the lower end of the material l is brought into contact with the step/7 of the fixed mold/g. Becomes under pressure.

At this time, the bottom part /6 of the material 1 is pressed down by traction pressure to prevent deformation of this part, the inner diameter of the material 1 is restrained by the male die 1/, and the upper part of the outer diameter is held by the female die 13. The lower part is restrained by the fixed mold /q. Therefore, when the shiram descends, the meat of the material has no choice but to protrude into the split mold 15. In this case, if the split die /S does not exist, the cylindrical portion of the material 1 will bulge in the outer circumferential direction, resulting in a bulging process that is commonly performed. In this invention, the split mold ls presses the outer periphery with a planned pressure, and while preventing swelling and sagging, excess meat is allowed to protrude from this area. This means that the amount of shrinkage caused by compressing the length of the cylindrical portion of the material has been transferred to the thickened portion.

What becomes a problem in the above-mentioned thickness increasing process is the pressing force of 1 toward the center of the split mold/S. If this is too small, the above-mentioned bulge process will occur, but if the pressure is low enough to prevent this, wavy wrinkles will occur. Also, if you use a slightly higher pressure,
A large force is applied to the mold, which may cause damage. Originally, this process is different from general sheet metal pressing processes such as drawing and bending processes, and is a type of cold forging process in which a tremendous force is applied to the die. Therefore, unless the pressing force of the split mold 15 is precisely controlled, mold breakage, quality defects, etc. may occur frequently. This control method will be described later.

Thickening is complete when the ram reaches its lowest point.

Thereafter, the ram is raised to remove the material 1, but prior to that, it is necessary to remove the pressing force of the split mold 15. This point will be discussed below. As the ram rises, the male mold // also rises due to the traction pressure. At this time, female! / and 7 are pushed downward by the elastic body l, but since the diameter of the thickened part of the material / is larger and the pressure force of the traction is greater, the male mold /l and the material l rises at the same speed as In this case, split 9 type 1
When the pressurizing force is applied to the mold 5, the split mold 15 also rises. Although this is dangerous, it is also a split type 1.
Since it is not possible to take out the charge until the ram is pressurized, it is necessary to remove this pressurizing force as soon as the ram starts to rise. In this way, when the ram is raised, the split mold 15 will remain in the same position, and the material l will remain in the split mold/S
I can get out of it.

As the ram rises further, the lower step of the male die /l hits the step -〇 of the fixed die lda, and the downward stroke of the cushion pin /g also ends here.
The rise of the male type // stops.

Accordingly, the rising of the material 1 is also stopped, and at the same time, the female die 13 is also stopped at that position. After this, the elastic body 19 expands as the ram rises, and finally the step 1 of the guide ring comes to engage with the upper step of the female die 13. From this point on, the female mold 13 rises with the ram. At this time,
The upper part of the cylindrical part of the material / is fitted between the lower part of the female mold 13 and the male mold //, but when the female mold 13 rises, the material I follows the female mold /3 and comes out of the male mold //. become.

However, there is no guarantee that the material / will always come out of the male mold //, but empirically speaking, there is a high probability that the material l will rise with respect to the female mold 13. If there is a risk that the material l will not rise to the female mold/3 and remain in the male mold//, a squirting device (not shown) is provided inside the male mold so that the material l does not rise to the female mold/3. You need to make sure that you follow this plan in a planned manner.

When the ram rises further and approaches top dead center, the ejection rod -
3 pushes the knockout 7.2 and pulls out the material l from the female mold 13.

In the above, the effect of this thickening type was explained in detail.
In this explanation, detailed explanations of matters that can be understood just by looking at the drawings and common knowledge regarding mold technology and press technology, such as methods of fixing mold parts, are omitted.

As shown in Figure 9, which shows a cross-section of the split mold/S and its surroundings, with some hatching omitted, the split mold/S has a radial shape due to the enlargement of its outer diameter. In order to prevent the gap from becoming large (C), the number of divisions is large. 2 Da indicates the packing that surrounds the split mold, which has a cross section as shown in Fig. The diameter increases or decreases depending on the diameter variation of /S.

Although this is not inherently desirable, in this case the amount is small and is sufficient for practical purposes, and by allowing this, a simple structure can be obtained. The symbol indicates a cylinder,
It has a structure that can withstand high pressure. Between the packing cog and the cylinder 6 is a high pressure chamber created by hydraulic pressure, the passage of which is indicated by the reference numeral core in FIG. 3 arranged around the outer periphery of the split mold
The corner piece 25 functions to prevent the packing material from digging into the gap created by the expansion of the split mold/S.

As shown by the chain line in FIG. 10, which is a partially enlarged view of FIG. 9, even if the diameter of the split mold 15 is increased and a gap a is created, the packing portion remains airtight.

f4jl In the thickening process described above, the split mold/S is pressurized toward the center, but this pressurizing force must be precisely controlled. 7. Means for achieving the control method
An example is diagrammatically illustrated on the right side of FIG.

In FIG. 5, the piston 2g, which together with the cylinder JO constitutes a source of oil pressure for pumping action, is returned upward by the action of the spring 3/. To achieve such operation, in the illustrated embodiment, the upper mold has an arm core, which is said to act on the piston-gK, but this is merely for illustrative purposes, and no arm, 29, actually exists. Not necessarily.

While the ram of the press is descending, the arm, 2q, hits the piston g.
When the piston 2g is pushed down, the oil located below the piston 2g passes through the passage 3.2 and reaches the cylinder holder, and also reaches the check valve 33, the pressure regulating valve 3hiro, and the side valve 3S; , at the beginning, the split mold 15 moves toward the center. As the ram descends further, the split mold/S reaches the end of its centerward movement. At this point, 1. This is just before the mold starts thickening. When the mold reaches the end of its centerward movement, the oil has nowhere to go and creates high pressure. This high pressure actuates pressure regulating valve 3, and oil enters tank 37 through passage 36. The ram continues to descend further, causing the mold to begin thickening.

From this point on, the diameter of the split mold 15 increases and the oil in the cylinder λ6 flows back through the passages 3 and is pushed by the piston 2g.

It joins with the oil coming out and enters tank 3 through pressure regulating valve 3. In this way, while the material 1 is being thickened, the pressure acting on the split mold/S is reduced by the pressure regulating valve 3.
The pressure is maintained at the set pressure value of q.

After that, when the ram starts to rise, the piston also rises by 2g, so the pressure decreases, but this descent usually occurs as follows:
Since each part is elastically deformed, it will not become too sudden. In order to overcome this difficulty, according to the present invention, a solenoid valve 35 that is operated in conjunction with the movement of the mold is arranged as shown in FIG. 5, thereby achieving ideal timing. It is now possible to do so. In this way 7
Therefore, ideal control of the split mold/S when the ram is raised can be achieved. Next, when the piston g returns due to the rise of the ram, the check valve JJ opens and the oil in the tank 37 is drawn up into the cylinder 30, thus preparing for the next operation.

In the above-mentioned thickness increasing method, the split mold/S can be pressurized in various ways, of which only seven examples are shown here. For example, it is conceivable to use a grip attached to the press 1, but this pressing force is much larger, and as the width of the thickened portion increases, the pressing force becomes larger than the pressure required for processing. In this respect, according to the above-described embodiment of the present invention that utilizes hydraulic pressure, equipment loss and energy loss are greatly reduced.

Next, the rolling process shown in FIG. 6 will be explained. In Figure 1/Figure 7.2 and Figure 7.2 showing each stage of rolling process, the first
The left side of the center line C in Figure 1 shows the state where rolling is starting, and the first
The right side of the center line C in Figure 1 shows the state when rolling is completed. Furthermore, these intermediate states are illustrated in the ml-diagram. The feature of this rolling process is that a material having approximately the same diameter as the flange portion S shown in Fig. 1 is used, the diameter of the material is reduced, and groove rolling is performed. The purpose is to form unevenness on the back side of the Kv mountain at the same time as the construction.

To explain Figure 1/Figure 12 and Figure 12, the code 0
indicates a rotary table, and at the center there is a guide pin t1. l is provided. After inserting the center hole of the material 1 into this, lowering the molds 1 to t7 located above results in the power distribution 1'' as shown in the figure. When attaching, the mold clamp tightens the bottom of the material l first.This tightening is done by attaching the mold clamp to the rotating shaft duct with the holder lI6,
It is constructed so that it can be rotated while applying pressure. Although the movable mold 3 on the outside of the mold 2 can be moved downward by a small amount, it is held at a fixed position by an elastic member 5 made of rubber or the like. In the lower part of this movable type 3, unevenness is formed. The pressurizing mold g+ surrounding the movable mold q3 is configured to achieve pressurization as it rotates. The symbol SO designates the work roll, which is held in place by a spring Sl.

In the state immediately before starting machining, which is illustrated on the left side of FIG. 1, the machining roll 50 is positioned in a fixed position by the spring Sl. Tightening is done by the mold Il, this tightening is done between the mold and the rotary table, and then the pressurized mold
is strongly pressing the end portion II9 of the material l. In this state, the mold ll-97 and the turntable 110-4! /And the entire material 1 is rotated, and the roll 50 is advanced toward the center of rotation. In doing so, first of all, the diameter of the material l becomes smaller.

Fig. 1 shows a state in which the diameter of the V sea portion is reduced and a flange portion is formed. At this time, the inner diameter of the cylindrical portion of the material 1 comes into contact with the outer diameter of the movable die 3, and unevenness begins to form in this portion of the material 1. ■As the finishing and processing progresses, the unevenness becomes deeper.

At this time, the following problem occurs. According to the experimental results, in the state shown in Figure 1, the flange part (the part indicated by the symbol S in Figure 1) is not complete, and therefore, in order to form a complete flange part, the material/ It is necessary to move the cylindrical part further downward. The force for this movement is received by the pressure type tough, but since the inner diameter of the cylindrical part of the material l is biting into the uneven groove g of the movable type 3, if the movable type 3 does not move, the pressure will not be applied. The pressure of the pressure mold tItI does not reach the downward direction, resulting in an uneven top and bottom.

In order to solve the problem described in the previous paragraph, according to this embodiment of the present invention, a moving m't3 is provided, and from the state shown in FIG. Start moving to. At this time, since the pressure of the elastic body 5 is extremely lower than that of the pressurized type ++, the influence of the pressure of this elastic body can be ignored. In this way, the mobile da
According to the method, the rolling process can be performed by making the pressing force of the pressurizing die as uniform as possible. However, when the number of grooves is small, the movable die q3 may be omitted and the tightening may be performed only by the die.

At the time of completion of processing, the movable type 'IJ is located at the lowest end while compressing the elastic body IIs, as shown on the right side of Fig. 1.

w, l1 When the roll SO is returned to the position before processing from the state on the right side of the figure and the upper mold group is pulled up, the material l follows. In the final stage, the clamping die q and the movable die 2 are moved in the direction of pulling out the material, whereby the rolled product is pulled out. In this way, a poly-V pulley as shown in FIG. 1 and FIG.

(2) The key points of this invention, in which unevenness is provided on the inner diameter portion of the back surface of the V tile in order to improve the machining accuracy of the grooves, will be explained below with reference to FIGS. 13 and 1.

As shown in the explanatory diagram in Figure #'13, a narrow cylindrical material 31 obtained by cutting a pipe is fitted around the core bar 50,
Let us consider the operation of rotating this and applying strong pressure to the flat roll 53 to plastically deform the cylindrical moon. This work is clearly a rolling process, and the diameter of the cylindrical material 5/ increases as the wall thickness becomes thinner, resulting in the state shown by the chain line. In contrast to the rolling process of the cylindrical material mentioned above, Holi v
In rolling the pulley, the diameter is constrained by the flange portion of the outer groove 1, so no change in diameter occurs in this area due to rolling. However, it is considered a natural result that the diameter increases as a result of rolling in the central region where this restraining force is weakened. Figure 1 shows this situation.

The solid line shows the planned shape, but the actual shape is shown by the dashed line.

According to this invention, when unevenness is provided on the inner diameter part of the back surface of the V-groove,
First, rolling during rolling is suppressed, and the increase in diameter at the center is extremely small, and the precision of the angle is also improved. Furthermore, by providing the unevenness, it is possible to obtain the effect that irregularities in the V-mountains due to lack of precision in the rolled portion where the thickness of the material is increased are absorbed by the unevenness. According to actual test results, a conventional 5-row V pulley with an outer diameter of 720 mm without unevenness had an angular error of ±30 at maximum, but the one with unevenness according to the present invention had an angular error of ±30. It was 10. This means that the effect of the unevenness is sufficient. Since this experiment is a comparative experiment, it is certain that even higher accuracy can be obtained by improving rolling conditions and other factors.

[Brief explanation of the drawing]

FIG. 1 shows the Po + J y pulley according to the present invention. The sectional view and calculation diagram taken along line -1 represent the poly-V pulley shown in FIG.
The plan view, FIG. 3, FIG. 3, S, and FIG. A cross-sectional view similar to Fig. 1 showing the entire shape of the material; Fig. 7 is an illustrative diagram showing the principle of the thickening method; Fig. 5 is a cross-sectional view showing the entire shape of the material. Fig. 9 is a cross-sectional view of the mold mainly passing through the axis, and diagrammatically schematically illustrating the associated hydraulic system. Enlarged view showing partially omitted, No. 10
The figure is an enlarged view of a part of Fig. 9 without hatching, and Fig. 1/ and Fig. 1J show the rolling device at each stage of the rolling process, mainly in vertical cross section passing through the axis. 13, and the first diagram are explanatory diagrams for clarifying the advantages of the present invention. In the drawings, l is a cylinder with a bottom, - is a v groove, da and S are 7 rung parts, 7 and g are unevenness of the cylinder part, IO
/, 2 and /4 are molds that compress the cylindrical part in the axial direction; /s is a split mold; 2g and 30 are hydraulic sources; 3
This is oil passage 1. j3, 3'1 and 3s are control mechanisms, q
O and t- are members that tighten the bottom, Da3 is a movable type, Rihiro is a member that presses the end of the cylindrical part, qg is a movable type unevenness, and sO is Fig. 7

Claims (1)

[Scope of Claims] 1. A sheet metal poly V pulley formed into a predetermined shape by plastic working of sheet metal material, characterized in that a large number of irregularities are formed on the inner diameter portion of the back surface of the groove portion on the outer circumferential surface thereof. Sheet metal poly V pulley. 2. By drawing the sheet metal material, a cylinder with a bottom having an outer diameter approximately equal to the flanges at both ends of the finished poly V pulley is formed, and in order to increase the thickness of the central part of the cylinder, the thickness is increased. All the inner and outer surfaces of the cylindrical part and the front and back sides of the bottom are restrained, except for the part where the thickness should be increased.A split mold whose diameter can be varied is placed around the part where the thickness should be increased, and the cylindrical part is compressed in the axial direction. While moving the material to the area where it should be thickened, the thickened area is formed, and at that time, pressure is applied to the split mold in the center direction to the extent that the material does not bend and become bulged. Then, while tightening the bottom of the cylinder with the bottom on which the thickened part is formed, the cylinder is rotated while applying strong pressure to the end of the cylinder in the axial direction. The diameter of this part of the cylinder is reduced by pressing an axially movable processing roll against the cylinder, first forming flange parts at both ends of the cylinder, and then forming a flange part on the inner diameter of the cylinder. By bringing a movable movable mold with corresponding unevenness into contact with the inner diameter of the back surface of the cylindrical portion, unevenness is formed on the inner diameter of the back surface of the cylindrical portion, and at the same time, a V groove is formed on the outer diameter of the surface of the cylindrical portion by a processing roll. 1. A method for manufacturing a sheet metal poly-V pulley, comprising the steps of processing. 3. Drawing processing means for forming a cylinder with a bottom by drawing a sheet metal material, thickening for increasing the thickness of the central portion of the cylindrical portion of the cylinder with a bottom formed by the drawing processing means and a sheet metal poly V by forming irregularities on the inner diameter of the back surface of the cylindrical portion and forming a V groove on the outer diameter of the surface of the cylinder with a bottom whose central portion is thickened by the thickness increasing means. In an apparatus for manufacturing a poly V pulley made of a sheet metal, which has a rolling means for forming a pulley, the thickness increasing means is configured to form a cylinder with a bottom that is restrained except for the portion to be thickened, and the portion to be thickened is a split mold disposed around the cylinder, a movable mold movable for axially compressing the cylindrical portion of said bottomed cylinder, a press ram movable for moving the movable mold, actuated by the movement of the press ram; The press ram is provided with a hydraulic source that performs a pumping action, an oil passage extending from the hydraulic source to around the split mold, and a control mechanism disposed in the oil passage, and when the press ram is moved to the bottom dead center by the control mechanism. At this time, a pressure in the center direction is applied to the split mold under high-pressure control by hydraulic pressure from a hydraulic source, and the pressure acting on the split mold is released when or before the press ram reaches the bottom dead center. A manufacturing device for a sheet metal poly V pulley, which is characterized by the following.