JPH0797121A - Cam screw and its manufacture - Google Patents

Abstract

PURPOSE:To provide a cam screw having a sufficient strength and accurate form and sizes capable of being manufactured with an injection mold easily. CONSTITUTION:A cam block 22 is fitted around a core material 21 made of metal and they are joined without gap. A protruding part 22b forming a spiral groove is arranged on the outer circumferential face of the block 22, and when joining is made without gap a continuous cam grove is formed. The core material 21 has on its outer circumference a plurality of grooves 21a in the axial direction and it is fitted to a linear projection formed on the inner circumferential face of the cam block, and the cam block 22 is fixed so that it may not turn around the core material 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a spiral cam groove on its peripheral surface, and reciprocally conveys a locking member supported so as to project into the cam groove by rotation and a member joined thereto. More particularly, the present invention relates to a cam screw that can be easily manufactured at low cost and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, a spiral cam groove is provided on a peripheral surface of a shaft, and a protrusion or a rotating body is engaged with the cam groove to rotate the shaft around an axis, whereby a member continuously provided with the protrusion or the like. A cam screw that reciprocates in the axial direction of the shaft is used. For example, in a copying machine, it is used to raise and lower a plurality of discharge trays in a sorter device.

Conventionally, such a cam screw has been manufactured by first manufacturing a columnar body and then cutting the cam groove in the outer periphery into a spiral shape or integrally molding the same by injection molding of plastic. However, in order to cut the spiral cam groove on the cylindrical body, special equipment for cutting is required, and the cutting process requires a long time. On the other hand, in injection molding, it is necessary to manufacture a mold having a complicated shape, and in addition, when molding a large cam screw, a large-sized mold and large-scale equipment are required. However, there was a drawback that the manufacturing efficiency was poor.

As a solution to this drawback, there is a method in which a cam block obtained by dividing the cam screw in the axial direction is injection-molded, and then a plurality of these cam blocks are connected to form a cam screw. In this case, since the cam block can have a simple shape, the mold can be easily manufactured, and a large-scale equipment for injection molding is not required. Therefore, efficient manufacturing is possible.

[0005]

However, as in the conventional method, by simply dividing and molding, a large number of cam blocks are assembled when a long cam screw is manufactured. There is a problem in that even if the connection portion is slightly displaced, the entire cam screw will be greatly deformed. Further, since it has a large number of connecting portions, it becomes a weak point as a member, and there is a problem that strength is deteriorated.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is that it does not require large-scale equipment or special equipment, can be efficiently manufactured, and has an accurate shape and size. A cam screw having various strengths and a method for manufacturing the same.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is a columnar body having a spiral groove formed on its peripheral surface, which is driven to rotate about an axis. A cam screw that reciprocally conveys a locking member arranged so as to project into the groove and a transported body continuously provided with the locking member substantially parallel to the axis of the columnar body,
A cam block that is divided into a plurality of parts in the axial direction, each of which has a cylindrical shape having through holes in the axial direction, and is arranged without gaps so that the through holes are continuous, and all of these cam blocks are arranged in the axial direction. A core member penetrating therethrough and closely inserted, and having engaging means for restricting relative displacement around the axis of the core member on both of the contact surfaces of the cam block and the core member. To do.

According to a second aspect of the present invention, in the cam screw according to the first aspect, the engaging means is a linear convex portion or a concave portion in the axial direction provided on the peripheral surface of the core member. A concave portion or a convex portion provided on the inner peripheral surface of the cam block and fitted with the convex portion or the concave portion.

According to a third aspect of the present invention, there is provided a method for manufacturing a cam screw having a spiral groove on a peripheral surface of a columnar body, wherein the cam screw is divided into a plurality of parts in the axial direction and has a through hole in the axial direction. The cam block is formed, a core material is inserted into the through hole of the cam block, and the plurality of cam blocks are arranged without gap in the axial direction of the core material.

In the first or second aspect of the invention, the transported object is a member supported so as to be reciprocable in a certain direction, such as a discharge tray in a copying machine. The specific material, shape, and size of each member constituting the cam screw can be appropriately selected unless otherwise specified. For example, the cam block may be made of any material as long as it has strength to engage a projection piece or a small wheel in a groove and carry a conveyed object continuously provided with the projection piece. What you can do is desirable. Further, the diameter and axial length of the cam block and the depth and width of the groove can be appropriately designed depending on the application and purpose. The plurality of cam blocks can be used by combining a plurality of types of cam blocks having different diameters, axial lengths, gradients of spiral grooves, and the like. On the other hand, the core material needs to have sufficient strength to fit into the through hole of the cam block and reinforce the cam screw, but even if it is of the same quality as the cam block, another material may be used. Good. Further, the cross-sectional shape of the core material needs to be a shape that can be fitted into the through hole, but may be circular or polygonal.

Further, the engaging means does not necessarily have to be provided between all the cam blocks and the core material. A cam block that is not provided with an engaging means can be fixed to an adjacent cam block by a key or the like, and can be restrained so that relative displacement with the core material does not occur.

[0012]

Since the cam screw according to the first aspect is formed by the cam blocks which are divided into a plurality of portions in the axial direction, each cam block can be molded to have a short axial dimension. Therefore, when molding, injection molding can be performed without requiring special equipment or large-scale equipment, and a mold for molding can be easily manufactured. For this reason, it can be manufactured much more efficiently than cutting or injection molding as one piece. Further, since the core material is fitted and inserted in the axial direction of all the cam blocks, each cam block can be accurately arranged, and a continuous cam groove can be formed on the peripheral surface. It is possible to smoothly convey the projecting piece or the like engaged with the cam groove. Further, by inserting the core material, the cam screw has sufficient strength and is less likely to be deformed. Further, by manufacturing a plurality of types of cam blocks and appropriately combining them, cam screws having grooves of different forms can be obtained, and cam screws of various patterns can be manufactured at low cost.

In the cam screw according to the second aspect of the present invention, linear convex portions or concave portions in the axial direction are provided on the peripheral surface of the core material and the inner peripheral surface of the cam block, respectively, and these are fitted together. Therefore, the assembly can be easily positioned during assembly, and the cam block and the core can be prevented from being displaced and deformed even when the driving force is transmitted to the core to rotate the core.

In the method of manufacturing a cam screw according to the third aspect, since the cam block divided into a plurality of parts in the axial direction is formed, a large-scale facility for injection molding or the like and a large mold are not required, and the efficiency is improved. It can be manufactured at low cost.
Also, since the core material is inserted into the through hole of the cam block and the plurality of cam blocks are arranged in the axial direction of the core material without any gap,
Accurate joining of the divided cam blocks becomes easy, and a cam screw having a smooth cam groove on its peripheral surface and sufficiently reinforced by a core material can be obtained at low cost.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side view showing a cam screw according to an embodiment of the present invention. This cam screw 20
Is applied to the sorter device 10 of the copying machine shown in FIG. 6 as a device for driving the discharge tray 12 up and down. As shown in FIG.
The main part is composed of a plurality of types of cam blocks that are fitted to each other and are joined together without a gap.

As shown in FIG. 2, the cam block (type A) 22 constituting the standard pitch portion has a spirally extending portion 22b constituting a groove on the outer periphery of a cylindrical portion 22a having a through hole in the axial direction. It is provided. Further, a joining key 22c is provided on the upper edge of the cylindrical portion 22a for accurate positioning when joining the adjacent cam block, and a joining key of the adjacent cam block is fitted on the lower edge of the cylindrical portion. A notch 22d to be fitted is provided. Further, a plurality of linear protrusions 22e are provided on the inner peripheral surface of the cylindrical portion 22a in parallel with the axis.

As shown in FIG. 3, the cam block (type B) 23, which constitutes the portion where the pitch of the spiral groove is changed, has a cylindrical portion 23a which is longer than the type A in the axial direction.
A spiral groove is provided on the outer peripheral surface of the, and the slope of the spiral groove changes, and the slope becomes steeper as it goes downward from the standard portion. Similar to the type A, a joining key 23c and a notch (not shown) are provided on the upper edge and the lower edge of the cylindrical portion, and an axial linear projection is formed on the inner peripheral surface of the cylindrical body. 23e is provided. Further, the cam block (type C) 24 and the cam block (type D) 25 have the same structure.

As shown in FIG. 4, the core material is a hollow cylindrical member made of steel, and has a plurality of grooves 21a on the outer peripheral surface in the axial direction. The grooves 21a are provided at equal intervals in the circumferential direction, and the cam blocks 22, 23, 2 are provided.
Linear projections 22e, 23 provided on the inner peripheral surfaces of 4, 25
The spacing and cross-section dimensions are such that a close fit with e is possible.

Next, an embodiment of the invention described in claim 3 which is a method of manufacturing such a cam screw will be described. Each type of cam block 22, 23, 2
4 and 25 are manufactured by injection molding of plastic.
At this time, the length of division into the cam blocks is appropriately determined so that the mold can be easily manufactured. As the core material 21, a general steel material is used, and the groove 21a of the cylindrical shape and the outer peripheral surface can be simultaneously formed by drawing. The injection-molded cam blocks 22, 23, 24, 25 are sequentially arranged in accordance with the combination pattern as shown in FIG.
Insert into 1. Then, the core material 21 is arranged in a predetermined position without a gap and completed.

Three such cam screws 20 are used in the sorter device 10 of the copying machine, and as shown in FIG. 6, they are arranged in the up-down direction and a plurality of discharge trays 12 are provided so as to be stacked. The periphery of is supported via wheels 11. As shown in FIG. 7, the sorter device 10 is a copying machine provided with a photosensitive drum 1, a charger 2, an exposure device 3, a developing device 4, a transfer device 5, a fixing device 6 and the like. It is provided in the ejected portion of the fixed paper, and ejects the paper which is ejected continuously while collating with a plurality of paper ejection trays 12. In such a sorter device 10, when the cam screw 20 is rotationally driven, the wheel 11 engaged with the cam groove 13 on the peripheral surface is guided by the cam groove 13 and moves in the vertical direction.
As a result, the paper discharge tray 12 moves in the vertical direction, and the paper is discharged to the respective paper discharge trays at this timing.

[0021]

As described above, the cam screw according to the first aspect of the invention is formed of a plurality of cam blocks that are divided in the axial direction, so that it is easy to manufacture each cam block by injection molding. Therefore, it can be efficiently and inexpensively manufactured. In addition, since the core material is inserted and inserted in the axial direction of all the cam blocks, it is possible to obtain a cam screw having sufficient strength and having each cam block accurately arranged and having a smooth cam groove. Further, by manufacturing a plurality of types of cam blocks and appropriately combining these, cam screws having grooves of different shapes can be obtained, and cam screws of various patterns can be manufactured at low cost.

In the cam screw according to the second aspect of the present invention, linear convex portions or concave portions in the axial direction are provided on the peripheral surface of the core material and the inner peripheral surface of the cam block, respectively, and these are fitted together. Therefore, a cam screw with high strength that does not deform can be obtained.

In the method of manufacturing a cam screw according to the third aspect, since the cam block divided into a plurality of parts in the axial direction is formed, it is possible to efficiently and inexpensively manufacture. Further, since the core material is inserted into the through hole of the cam block and the plurality of cam blocks are arranged in the axial direction of the core material without a gap, it is easy to accurately join the divided cam blocks, and the smooth cam groove is formed. It is possible to inexpensively obtain a cam screw having a peripheral surface and having been sufficiently reinforced by the core material.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a cam screw according to an embodiment of the invention described in claim 1 or claim 2. FIG.

2A and 2B are a side view, a top view, and a cross-sectional view showing a cam block (type A) used in the cam screw of FIG.

3A and 3B are a side view and a cross-sectional view showing a cam block (type B) used in the cam screw of FIG.

4A and 4B are a side view and a cross-sectional view showing a core material used in the cam screw of FIG.

5 is a schematic view showing a method of manufacturing the cam screw of FIG. 1, showing an embodiment of the invention described in claim 3. FIG.

6 is a schematic perspective view showing a sorter device of a copying machine using the cam screw of FIG.

FIG. 7 is a schematic configuration diagram of a copying machine using the sorter device shown in FIG.

[Explanation of symbols]

 1 Photoconductor 2 Charging Device 3 Exposure Device 4 Developing Device 5 Transfer Device 6 Fixing Device 10 Sorter Device 11 Wheels 12 Paper Ejection Tray 13 Cam Groove 20 Cam Screw 21 Core Material 22 Cam Block (Type A) 23 Cam Block (Type B) 24 Cam Block (Type C) 25 Cam Block (Type D)

Claims (3)

[Claims] 1. A columnar body having a spiral groove formed on a peripheral surface thereof, the locking member being driven to rotate about an axis and arranged to project into the groove, and the locking member connected to the locking member. In a cam screw that reciprocates an installed object to be reciprocated substantially parallel to the axis of the columnar body, the cam screw is divided into a plurality of parts in the axial direction and each has a cylindrical shape having through holes in the axial direction, and the through holes The cam blocks are arranged so as to be continuous without a gap, and the core material is inserted through the cam blocks in a close contact manner so as to penetrate all of the cam blocks, and both the contact surfaces of the cam block and the core material are provided. A cam screw, characterized in that it further comprises an engagement means for restraining a relative displacement of the core material around an axis. 2. The cam screw according to claim 1, wherein the engaging means includes a linear convex portion or a concave portion in an axial direction provided on a peripheral surface of the core member, and an inner peripheral surface of the cam block. A cam screw comprising a concave portion or a convex portion provided on a surface and fitted with the convex portion or the concave portion. 3. A method of manufacturing a cam screw having a spiral groove on a peripheral surface of a columnar body, wherein a cylindrical cam block having a plurality of axially-divided through holes is formed. A method of manufacturing a cam screw, wherein a core material is inserted into a through hole of the cam block, and the plurality of cam blocks are arranged in the axial direction of the core material without any gap.