JPH1177783A - Apparatus and method for molding magnet roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the generation of burr in a longitudinal direction at the end part of a magnet roll and to certainly avoid that a slide mold is not smoothly moved or the shaft part of the molded magnet roll is shifted with respect to a magnet roll main body in an apparatus for molding the magnet roll used in the electrophotographic developing device of a printer or the like. SOLUTION: A magnet roll molding apparatus includes a control means 18 consisting of a first controller protruding to a position flush with the surface of a fixed mold 8 or retracted therefrom until the rear end part in the moving direction of a slide mold 12 passes a plurality of projected pins 13 to operate the projected pins 13, a second controller protruding the projected pins 13 into a set distance molding space 11 from the surface of the fixed mold 8 after the rear end part in the moving direction of the slide mold passes the projected pins 13 and a third controller protruding all of the projected pins 13 in order to separate the molded magnet roll from the fixed mold 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet roll used for an electrophotographic developing device such as a copying machine, a facsimile, a printer, and the like, and to a molding device and a molding method for a magnet roll used for other purposes. .

[0002]

2. Description of the Related Art As a molding apparatus of the above-mentioned magnet roll, a vertical punching type molding method using a cylindrical mold having an injection port for injecting a molten magnet material at one end, and a fixed side mold are used. There is a split molding method using a split mold composed of a movable mold, but the latter molding method is often adopted from the viewpoint of ease of mold production and versatility of a molding machine. In addition to the latter molding method, as shown in Japanese Patent Application No. 8-335463 previously proposed by the present applicant, by disposing a movable slide mold in a molding space,
Uniformity of magnetic properties in the longitudinal direction of the magnet roll formed by the mold, stabilization of mechanical properties, and the like can also be achieved. Also, when using the split molding method, in order to easily remove the molded magnet roll from the fixed mold, a plurality of protrusions for pressing the molded magnet roll at a plurality of longitudinal positions thereof. The pin is provided in the fixed mold so as to be able to move freely. For example, as shown in FIG.
It is conceivable that the plurality of protruding pins 31... Connected by the connecting rods 30 can be integrally moved out and back by an actuator (not shown).

In the retracted position of the protruding pin, it is best if the tip of the protruding pin is flush with the inner surface of the fixed mold, but it is very difficult to precisely adjust the position. In addition, the tip of the protruding pin may be worn due to repeated contact with the formed magnet roll, and the tip of the protruding pin may be displaced backward.

When the tip of the protruding pin is retracted from the inner surface of the fixed mold as described above, the molten magnet material enters the protruding and retracting groove of the protruding pin formed in the fixed mold. Because of this, the outer diameter of the magnet roll in that part becomes large, not only does quality problems such as contact with other parts occur during use, but also when removing the molded magnet roll from the fixed mold The part of the magnet roll stuck in the groove for the protrusion and retraction of the protrusion pin must also be pushed out by the protrusion pin, which not only requires a large protrusion force by the protrusion pin but also deforms the protrusion pin in some cases. Or was damaged.
Further, when the slide die 32 is retracted after the movable die 9 is separated and the slide die 32 is separated from the end of the magnet roll, the molten metal that has entered the groove for the protrusion and retraction of the plurality of protrusion pins is used. Since the binding force with the magnet material is weaker than the binding force between the end of the magnet roll and the slide mold 32,
Even when the slide mold 32 is retracted, the magnet roll 1 may move while being stuck, and the slide mold 32 may not be able to be separated from the end of the magnet roll.

In order to solve the above problem, it is general that the tip of the protruding pin 31 is protruded from the inner surface of the fixed mold 8 by a set distance as shown in FIG. Therefore, a part of the slide die 32 is cut out along the longitudinal direction so that the slide die 32 can be allowed to move with the tip of the protrusion pin 31 protruding, and the notch 33 is formed. The projecting pin 31 is configured to always move.

When the notch 33 is formed as described above, the molten magnet material to be filled may enter the notch 33, and the end of the magnet roll 1, that is, the shaft, may have burrs in the longitudinal direction. Good movement of the slide mold 32 is caused, for example, by causing the molten magnet material to enter or stay inside the notch portion 33 and solidified, and the solidified molten magnet material gives resistance to the movement of the slide mold 32. Sometimes I couldn't. Further, the slide die 32 may be loosened in the molding space due to the cutout 33, and the shaft of the magnet roll 1 to be molded may be shifted with respect to the magnet roll body.

[0007]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present invention is intended to solve the problem of avoiding the generation of burrs in the longitudinal direction at the ends of the magnet roll and making the slide type move smoothly. This is to ensure that it is possible to avoid that it cannot be performed easily and that the shaft portion of the molded magnet roll is displaced from the magnet roll body.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a split mold comprising a fixed mold and a movable mold, and a retractable mold which can be moved into and out of a molding space of the split mold. And a slide die for moving to the retreat side to form one end of the magnet roll with the filling of the molten magnet material into the molding space, and the molded magnet roll being fixed to the fixed side. A plurality of protruding pins that are capable of retracting and pressing the magnet roll at a plurality of locations in a longitudinal direction of the magnet roll in order to release the slide mold from the mold when the molten magnet material is filled into the molding space. When moving to the side, the projecting pin is located at a retracted position flush with or more than the mold surface of the fixed mold until the rear end in the moving direction of the slide mold passes through the plurality of projecting pins. The first control that operates After the rear end of the slide die in the moving direction has passed through the projecting pin, a second control for projecting the projecting pin from the mold surface of the fixed mold into a set distance forming space, and forming the formed magnet roll A control means is provided which includes a third control for projecting the entire projecting pin in order to release the pin from the fixed mold. Therefore, by operating the protruding pin to the retreat position flush with or more than the mold surface of the fixed mold until the slide mold passes, the slide mold protrudes and contacts the pin when the slide mold moves. It is possible to operate from the forward position to the retracted position without hitting, and it is not necessary to form a notch for avoiding the projecting pin in the slide mold as in the conventional case. As a result, it is possible not only to prevent burrs from being generated at the ends, but also to smoothly move the slide mold, and the shaft of the formed magnet roll is shifted with respect to the magnet roll body. Can be reliably avoided. Then, when the tip of the protruding pin is retracted from the surface of the mold of the fixed mold, the rear end of the slide mold in the moving direction passes through the protruding pin, and then the protruding pin is moved to the mold of the fixed mold. The molten magnet material, which is protruded from the surface into the molding space at a set distance and has entered the groove for the protrusion and retraction of the protruding pin, can be pushed into the molding space side by the protruding pin with fluidity. When the filling of the molten magnet material into the molding space is completed and the molten magnet material is solidified, all the protruding pins are projected, and the molded magnet roll is separated from the fixed mold. The protrusion pins are periodically replaced, or the position of the tip of the protrusion pins is periodically adjusted to a predetermined position, so that the protrusion pins are set a predetermined distance from the mold surface of the fixed mold. You can always project inside.

In the second control, the projecting pin is projected from the mold surface of the fixed mold into the molding space for a set distance immediately after the rear end of the slide mold in the moving direction has passed the projecting pin. It is characterized by. That is, when the slide die moves to the retreat side, the slide die moves to a position retracted from the die surface of the fixed die as in claim 1 until the rear end in the moving direction of the slide die passes through the protrusion pin. Since the protruding pin is located, the slide die does not contact the protruding pin. Immediately after the rear end in the moving direction of the slide die passes through the protruding pin, the protruding pin protrudes from the mold surface of the fixed mold into the molding space for a set distance, thereby forming a groove for projecting and retracting the protruding pin. In particular, the operation of projecting the protruding pin located on the molten magnet material injection port side is more fluid than that of protruding the protruding pin after the slide mold has passed the protruding pin through the entire protruding pin. In this state, it can be smoothly pushed into the molding space.

The projecting pin comprises a fixed cylinder part penetratingly fixed to the fixed mold, and a pin body movably provided in the fixed cylinder part. By being detachable from the mold, it is possible to replace only the fixed-side cylindrical portion that is worn due to the retracting operation of the pin body, which is advantageous in terms of cost as compared with the case where the entire mold is replaced. be able to.

By forming the protrusion pins from a non-magnetic material, the orientation direction of the magnetic particles of the magnet roll to be formed is not disturbed by the protrusion pins.

By providing the control means on the magnet roll forming apparatus side, the soft surface for forming the magnet roll is changed, and a slight hardware mechanism is added.
A special hardware configuration for the mold can be eliminated.

By filling a molten mold material into a split mold composed of a fixed mold and a movable mold, the slide mold movably disposed in the molding space is moved to the retreat side, At the time of this retreat, immediately after the rear end of the slide die in the moving direction has passed through the protruding pin, the protruding pin protrudes from the die surface of the fixed side die into the molding space for a set distance, and the inside of the molding space is moved. Filled with molten magnet material,
A method of forming a magnet roll, wherein a magnet roll is formed, and after the formation, the fully projecting pin is further protruded from the protruding position to detach the magnet roll from the fixed-side mold is established.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The configuration of the magnet material-integrated magnet roll, its forming apparatus and its forming method will be described. FIG. 1 shows a magnet roll formed by using the forming apparatus of the present invention.
Is formed by projecting shaft portions 3 and 4 with reduced diameters at both ends of a cylindrical roll portion 2 and forming notches 5 for positioning or driving force transmission on the shaft portion 3 and integrally formed by using a magnet material. Is molded. In addition, as the magnet roll 1, the roll part 2
Is not a cylinder, but a polygonal pillar, the other shaft part 4, or both of the shaft parts 3, 4, the notch 5 is formed, or the center of the roll part 2 and the axes of the shaft parts 3, 4. The present invention can be similarly applied to a case where the center is intentionally eccentric.

The magnetic material constituting the magnet roll 1 is mainly composed of a magnetic powder and a binder for binding the magnetic powder, and a silane-based or titanate-based coupling agent for strengthening the bond, A mixture containing a small amount of a lubricant to improve fluidity, a stabilizer to prevent thermal decomposition of the binder, etc.It is also possible to add a flame retardant, a reinforcing agent, etc. if necessary. , Rare earth (SmCo, NdFeB)
System), MnAIC system, alnico system, SmFeN system, etc., and as the binder, a thermoplastic resin, a thermosetting resin, a low melting point alloy or the like can be used.

The magnet roll 1 is used as a developing roll or a cleaning roll in an electrophotographic developing device such as a copying machine, a facsimile, a printer, or the like, but can be used for other purposes.

Next, an outline of the molding device 6 for the magnet roll 1 will be described. As shown in FIGS. 2 and 3 (a) and (b) to FIGS. 4 (a) and 4 (b), a split mold 10 including a fixed mold 8 and a movable mold 9 and a split mold Mold 1
0, and is disposed in the molding space 11 so as to be able to move back and forth with the filling of the molding space 11 with the molten magnet material.
, And a plurality of protruding and retractable protruding pins 13 a, which press the magnet roll 1 at a plurality of positions in the longitudinal direction thereof to release the formed magnet roll 1 from the fixed mold 8. 13b, 13c,
A magnetic field for aligning the direction of magnetic particles during a period until the molten magnet material provided in the movable mold 9 and the fixed mold 8 (not shown) and filled in the molding space 11 is solidified. Orientation means 14. As the magnetic field orienting means 14, various existing configurations such as a permanent magnet, an electromagnet, or a combination thereof can be used. The molten magnet material is supplied from an injection cylinder (not shown) into the molding space 11 through the injection port 20 shown in the drawing. Reference numeral 15 shown in the drawing denotes a magnet magnet that is used to move the magnet roll 1 back together with the slide mold 12 when the slide mold 12 is retracted in order to remove the slide mold 12 from the formed magnet roll 1. It is a rod-shaped body to be pressed against the material filling side. The protruding pin 1
Preferably, 3a, 13b and 13c are made of a non-magnetic material such as a non-magnetic metal, a synthetic resin or hard glass, or a ceramic.

On the basis of the detection result of the position detecting means 16 of the slide die 12, the protrusion pins 13a, 13b,
13c to drive each of the driving means 17c separately.
Control means 18 for outputting a drive signal to a, 17b and 17c are provided. The control means 18 is provided in the forming device 6 of the magnet roll 1 and is incorporated in a control device for driving various devices when performing the forming process of the forming device 6. 19 shown in the figure is a slide mold 12
It is a driving means for moving out. The driving means 17
a, 17b, 17c and 19 are, for example, hydraulic cylinders,
Pneumatic cylinders, screw screws, rack and pinion gears, linear motors and the like can be used.

The position detecting means 16 includes a slide type 12
Is detected directly by a contact-type or non-contact-type sensor, and the drive position of the driving means 19 for moving the slide die 12 is detected by a contact-type or non-contact-type sensor, and the slide is detected. The position of the mold 12 may be indirectly determined.

Next, a method of forming the magnet roll 1 will be described. First, as shown in FIG. 3A, the movable mold 9 is moved to the fixed mold 8 by a drive means (not shown) so that the molding space 11 can be formed, and then the drive means 19 is driven. The slide mold 12 is moved to the forward position. Before moving the slide die 12 to the forward position, the projecting pins 13a, 13b, 13c are moved to a retracted position retracted into the mold from the surface of the mold (first control). The protruding pins 13a, 13
A position where b and 13c are flush with the surface of the mold may be set as a retreat position.

Next, as shown in FIG. 3B, the injection cylinder is driven to inject and inject the molten magnet material into the molding space 11 through the injection port 20, and the injection pressure of the molten magnet material or the molten magnet material is injected. The molten space is filled with the molten magnet material while the slide mold 12 is retracted to the retracted position by the combined force of the material injection pressure and the driving force of the driving means. With the position detecting means 16
The slide type 12 is detected by the detected position information.
13a or 13b or 1
3c, the control unit 18 outputs a drive signal to the drive unit 17a or 17b or 17c immediately after that, and the protrusion pin 13a or 13b or 13c is output.
c is made to protrude from the die surface into the set distance forming space 11 (second control). In FIG. 3 (b), the rear end of the slide die 12 in the moving direction passes through the protrusion pin 13a located closest to the injection port 20, and immediately thereafter, the protrusion pin 13a is moved from the mold surface to the set distance molding space 11 by a predetermined distance. FIG. 4A shows a state in which the projecting pin 13 is located in the middle.
4B, the rear end of the slide die 12 in the moving direction has passed, and immediately after that, the projecting pin 13b is projected from the die surface into the set distance molding space 11, and FIG.
Projection pin 13c farthest from injection port 20
Is passed through the rear end of the slide die 12 in the moving direction. Immediately after that, the projecting pin 13c is projected from the die surface into the molding space 11 for a set distance, and then the slide die 12 is moved to the retracted position. Is shown. The set distance indicates a range from several tens of μm to several thousand μm.
Any distance may be set. When a hydraulic cylinder is used as the driving means, the molding oil is filled in the molding space 11 without gaps by applying a braking force to the backward movement of the slide die 12 by squeezing and leaking hydraulic oil. It becomes possible to go. However, a braking force applying means for applying a braking force by friction or the like may be provided to apply the braking force when the slide die 12 moves backward. Further, the slide mold 12 may be retracted while applying a braking force by the driving means in accordance with the injection speed of the molten magnet material. Further, when the molten magnet material is filled, the driving by the driving means may be stopped. Further, at this time, the direction of the magnetic particles is aligned by the magnetic field orientation means 14 until the molten magnet material filled in the molding space 11 is solidified.

Next, as shown in FIG. 5A, after the injected and injected molten magnet material is solidified, the movable mold 9 is moved away from the fixed mold 8 and then the slide mold 12 is moved. Retreat further. Thereafter, as shown in FIG. 5 (b), a drive signal is outputted from the control means 18 to all the driving means 17a, 17b, 17c, and all the pins 13a, 13b, 13c are made to protrude (third control). , Fixed mold 8 and rod 15
The magnet roll 1 is separated from the magnet roll 1 to obtain the formed magnet roll 1. The rod 15 is used to hold down the magnet roll 1 in order to move the slide mold 12 backward to separate the magnet roll 1. However, the rod 15 may be omitted. That is, since the protruding pins 13a, 13b, and 13c enter a part of the magnet roll 1, a locking action works between the two, and even if the slide die 12 is retracted, the magnet roll 1 is stuck and retracted. Therefore, the rod 15 may be omitted.

The protruding pins 13a, 13b, 13c
When the number of protrusions reaches the set number of times,
Since the tips of a, 13b, and 13c are worn, the protrusion pins 13a, 13b, and 13c must be replaced.
The inner surface of the fixed mold 8 that movably supports the protruding pins 13a, 13b, and 13c, particularly the upper corner, is worn to form a concave portion. Has a larger outer diameter at that portion, and the fixed mold 8 itself needs to be replaced, which leads to an increase in cost. Therefore, the projecting pins 13a,
If the components 13b and 13c are configured as shown in FIG. 7, it is possible to avoid an increase in cost. That is, the fixed-side cylindrical portion 13A penetrated and fixed to the fixed-side mold 8, and the pin body 13 movably provided in the fixed-side cylindrical portion 13A.
B, and the fixed side cylindrical portion 13A is fitted to the fixed side mold 8 so as to be detachable. Therefore, when the inner surface of the fixed-side cylindrical portion 13A, particularly the upper corner portion 13K, is worn by the movement of the pin body 13B, the fixed-side cylindrical portion 13A is removed and a new fixed-side cylindrical portion 13A is mounted. By forming a flange 13C at the lower end of the pin body 13B, a position at which the flange 13C contacts the fixed mold 8 when the fixed cylindrical part 13A is fitted to the fixed mold 8. By pressing the fixed side mold 8 to the upper side, the mold surface of the fixed side mold 8 and the upper end surface of the fixed side cylindrical portion 13A are flush with each other. The fixed side cylindrical portion 13A is replaced with a flange portion 13C.
It may be formed in a cylindrical shape without any. In addition, the fixed side tubular portion 1
The 3A may be fixed to the fixed mold 8 with screws or the like.
Further, the pin body 13B may be made of a material that is hard to wear, the fixed cylinder part 13A may be made of a material that is hard to wear, or the surface of the pin body 13B or the inner surface of the fixed cylinder part 13A may be formed. It may be carried out by mounting a wear-resistant member.

In the above embodiment, a plurality of projecting pins 13
a, 13b, and 13c are individually driven, but as shown in FIG. 6, a plurality of projecting pins 13a, 13b, and 1c are driven.
3c are connected by connecting rods 21, and all projecting pins 13a, 13b,
A driving means 17 for operating the retracting operation of 13c is provided,
Control means 18 for outputting a drive signal to drive means 17 based on detection information from position detection means 16 for detecting the position of slide die 12 may be provided. in this case,
All the protruding pins 13a, 13b, 13c are
When the rear end portion in the moving direction of the boss passes through, the entire projecting pins 13a, 13b, and 13c are made to project from the mold surface into the set distance forming space 11, as shown in the figure. At the time when the rear end in the moving direction of the slide die 12 has passed through 13b, 13c, the molten magnet material is maintained in a state where it is not completely solidified. In this way, it is only necessary to provide a single drive means 17 for operating the all projecting pins 13a, 13b, 13c in and out.
The control contents can be simplified as compared with those operated separately, which is advantageous in terms of cost and maintenance.

In the above embodiment, the shaft portion and the roll portion are integrally formed. However, the present invention is also applicable to a shaft insert type magnet roll in which a metal or synthetic resin shaft is inserted. Can be adapted.

[0026]

According to the first aspect, by controlling the driving of the plurality of protrusion pins in three stages, the slide mold is operated from the advance position to the retracted position without contacting the protrusion pins when the slide mold moves. Therefore, it is not necessary to form a notch for avoiding the projecting pin in the slide mold as in the related art. As a result, it is possible to avoid the occurrence of burrs in the longitudinal direction at the end of the magnet roll, to smoothly move the slide die, and to make the shaft of the magnet roll to be formed by the magnet roll. The displacement with respect to the main body can be reliably avoided. Further, when the plurality of protrusion pins are driven at a time, a single driving means can be used, and the control contents can be simplified as compared with those operated separately, thereby reducing cost and maintenance. There are advantages in terms of advantages.

According to the second or sixth aspect, immediately after the rear end in the moving direction of the slide die passes through the protruding pin, the protruding pin protrudes from the die surface of the fixed die into the molding space for the set distance. By doing so, the molten magnet material that has entered the grooves for projecting and retracting the ejecting pins can be pushed into the molding space in a state where there is sufficient fluidity. As compared with the case where the projecting pin projects from the mold surface into the molding space at the set distance, the projecting pin can be moved to the projecting position more smoothly, and more favorable molding can be performed.

According to the third aspect of the present invention, since the fixed side tubular portion is configured to be replaceable, the entire mold is not replaced, which is advantageous in terms of cost.

According to the fourth aspect of the present invention, since the projecting pins are made of a non-magnetic material, the orientation direction of the magnetic particles of the magnet roll to be formed is not disturbed by the projecting pins, so that the magnetic properties caused by the projecting pins can be reduced. It is possible to provide an uninvited magnet roll.

According to the fifth aspect, the change of the software surface and the addition of a slight hardware mechanism eliminate the need for a special hardware configuration for the mold, thereby suppressing an increase in the size of the apparatus.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnet roll integrated with a magnet material.

FIG. 2 is a sectional view schematically showing a molding apparatus according to the present invention.

FIG. 3 is a schematic cross-sectional view of a molding apparatus, in which (a) shows a state immediately before a molten magnet material is injected into a molding space;
(B) shows a state in which the molten magnet material is injected into the molding space from the state of (a).

FIG. 4 is a schematic cross-sectional view of a molding apparatus, and FIG.
(B) shows a state where the molten magnet material is further injected, and (b) shows a state where the injection of the molten magnet material is completed.

FIG. 5 is a schematic cross-sectional view of a molding apparatus, (A) shows a state in which a movable mold is separated from a molded magnet roll, and (B) shows a magnet molded from a fixed mold. The state where the roll is detached is shown.

FIG. 6 is a schematic sectional view showing another embodiment of the molding apparatus of the present invention.

FIG. 7 is a sectional view of a main part showing another form of the protruding member.

FIG. 8 is a sectional view schematically showing a conventional molding apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Magnet roll 2 Roll part 3 Shaft part 4 Shaft part 5 Notch part 6 Molding device 8 Fixed side die 9 Movable side die 10 Split die 11 Molding space 12 Slide type 13a, 13b, 13c Protruding pin 13A Fixed side cylindrical part 13B Pin body 13C Flange section 13K corner section 14 Magnetic field orienting means 15 Rod 16 Position detecting means 17, 17a, 17b, 17c Driving means 18 Control means 19 Driving means 20 Inlet 21 Connecting rod 30 Connecting rod 31 Projection pin 32 Slide type 33 Notch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29L 31:32

Claims (6)

[Claims] 1. A split mold comprising a fixed mold and a movable mold, and a molten magnet material which is disposed so as to be able to move in and out of a molding space of the divided mold, and is provided in the molding space. Along with the filling, a slide die for moving to the retreat side to form one end of the magnet roll, and a plurality of the magnet rolls in the longitudinal direction thereof for releasing the formed magnet roll from the fixed die. A plurality of protruding pins that can be extended and retracted to press at a location, and along with filling of the molten magnet material into the molding space, when the slide die moves to the retreat side, the rear end in the movement direction of the slide die is A first control for operating the protruding pin at a retracted position flush with or more than the mold surface of the fixed side mold until passing through the plurality of protruding pins; and a rear end of the slide mold in the moving direction. Passes through the protruding pin After that, the second control for projecting the projecting pins from the mold surface of the fixed mold into the set distance molding space, and fully projecting pins for releasing the molded magnet roll from the fixed mold. An apparatus for forming a magnet roll, further comprising control means for performing a third control for projecting. 2. The second control is such that, immediately after the rear end of the slide die in the moving direction has passed through the protruding pin, the protruding pin is protruded from a die surface of the fixed die into a molding space for a set distance. The magnet roll forming apparatus according to claim 1, wherein the magnet roll is formed. 3. The fixed-side cylindrical portion, wherein the projecting pin includes a fixed-side cylindrical portion penetratingly fixed to a fixed-side mold, and a pin body movably provided in the fixed-side cylindrical portion. 3. The method according to claim 1, wherein the side mold is detachable.
An apparatus for forming a magnet roll as described above. 4. The apparatus for forming a magnet roll according to claim 1, wherein said projecting pin is made of a non-magnetic material. 5. The magnet roll forming apparatus according to claim 1, wherein said control means is provided on a magnet roll forming apparatus side. 6. A slide mold movably disposed in a molding space is moved to a retreat side by filling a molten mold material into a split mold composed of a fixed mold and a movable mold. During this retreat, immediately after the rear end in the moving direction of the slide die has passed through the protruding pin, the protruding pin is protruded from the die surface of the fixed side die into the molding space for a set distance to form the molding space. The inside is filled with a molten magnet material to form a magnet roll, and after the formation, the fully protruding pins are further protruded from the protruding position to release the magnet roll from the fixed mold. Molding method.