JPH0328526A - Small-sized solenoid clutch mechanism - Google Patents

Abstract

PURPOSE:To reduce a cost of a solenoid clutch and secure reliability in durabil ity by preparing a cup-like shape yoke and a cylindrical part on the center thereof made of solenoid material plate. CONSTITUTION:A yoke 1 is fixed by means of an interference of a driving body 5 and the yoke 1. The yoke 1 has a thin cup-like shape, and an outer peripheral end face 1-b thereof is in contact to an attraction plate 4. A cylindri cal part is formed with deep drawing in the yoke 1 coaxially therewith. A part of the attraction plate 4 opposite to the yoke cylindrical part is recessed. A gap S is regulated by the rate of the recession. A small-sized solenoid clutch is produced with a low cost, while the reliability in durability is secured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intermittent power transmission mechanism, More specifically, the present invention relates to a small electromagnetic clutch mechanism that is often used as an intermittent paper feeding means or a trigger means.

[Conventional technology] In recent years, the electromagnetic clutch machines used for these applications are
For the purpose of ensuring reliability, reducing power consumption during operation, and simplifying the mechanism, a small electromagnetic clutch mechanism using a cup-shaped yoke is preferably used. This is achieved by keeping the suction plate in constant contact with the constantly rotating yoke while the printing device is in operation, and by energizing the electromagnetic coil, a suction force is generated between the yoke and the suction plate, which reduces the frictional force on the contact surface. This is a type of power transmission. A conventional electromagnetic clutch mechanism of this type uses a yoke having a shape as shown in FIG. 9, and in order to obtain the shape of the yoke, a nine bar material was used and lathed. It should be noted that the manufacturing cost of yoke components accounts for more than half of the cost of lateral parts of this type of electromagnetic clutch machine.

[Solution to be Solved by the Invention] However, in the above-mentioned prior art, the time required for parts processing,
In other words, the cycle time is very long (approximately 1.5 minutes), and in order to ensure the accuracy of the air gap δ in Figure 9, it is difficult to manage tools during yoke machining. The cost was high. Furthermore, when operating a device that incorporates this small electromagnetic clutch, it attracts the clutch and rotates as a unit only when switching operations is required.
Normally, the yoke and the suction plate are in sliding contact with each other, which has the drawback of being easily worn out and reducing reliability. In many cases, efforts are made to apply high-hardness plating to the yoke and suction plate and further reduce wear with lubricating oil, but due to the required characteristics of the lubricating oil, if the viscosity is increased, the suction plate will rotate around and malfunction. This necessitates the use of low-viscosity lubricating oil, which poses a problem of poor oil retention due to scattering.

The present invention has been made in view of these drawbacks, and its purpose is to provide a compact electromagnetic clutch that is much lower in cost. Another purpose is to prevent deterioration in reliability due to wear and ensure durability over time.

[ii! ll! [Means for Solving Problem i] First, in order to provide a low-cost small electromagnetic clutch, the present invention uses deep drawing processing instead of cutting processing for the yoke, and after deep drawing, trims the edges caused by deep drawing. A yoke is formed, and the accuracy of the air gap δ after the electromagnetic clutch is assembled is ensured by the concavity of the suction plate.

[Function] According to the above configuration of the present invention, the yoke can be machined by deep drawing instead of cutting to produce a component shape in a short cycle time, and the air gap δ after assembling the electromagnetic clutch can be reduced. Tool management is simplified because ensuring accuracy does not depend on accuracy control during lathe machining. [Embodiment] FIG. 1 is a perspective view showing the configuration of a small electromagnetic clutch in an embodiment of the present invention, and FIG. 2 is a sectional view of the same content. In FIG. 1, reference numeral 5 denotes a driving body which rotates by being driven by power, and the yoke 1 is fixed to this by the interference between the cantering body 5 and the yoke 1 with the pin 5-a passing through the hole 1-a. Alternatively, it may be fixed by caulking after penetration. As shown, the yoke 1 has a thin cup shape, and the outer circumferential end surface 1-b of the yoke contacts the suction plate 4 (the manufacturing process of the yoke 1 will be described later). Inside the yoke 1, a cylindrical portion (so-called iron core) 1-c is coaxially formed by deep drawing. By the way, a plurality of grooves are formed in the outer peripheral end surface 1-b of the yoke, as shown in an enlarged view in FIG. In the case of this embodiment, the depth of this groove portion is approximately 0.1+n, and the pitch between each groove is approximately 0.1+n.
2 mml: Set. Note that this groove may be composed of a plurality of concentric grooves or a single spiral groove, but either of these grooves is possible. These grooves are provided to store lubricating oil (not shown) to be applied to the contact/sliding surface between the outer peripheral end surface 1-b of the yoke and the suction plate 4.

As shown in FIGS. 3 and 4, the suction plate 4 has a concave shape at a portion facing the yoke cylindrical portion 1-c, and the gap δ is defined by the amount of the concavity. The gap δ is a gap between the outer peripheral end surface (cylindrical portion 1-C) of the yoke l and the suction plate recess, and means the amount of recess of the suction plate concave shape. An electromagnetic coil 3 is loosely fitted around the outer periphery of the cylindrical portion 1 - c and is disposed within a space formed by the yoke 1 and the suction plate 4 . Furthermore, the suction plate 4 has a starfish shape as shown in FIG. 4, and is configured to maintain stable contact with the outer peripheral end surface l1b of the yoke by being supported at three points. Moreover, this suction plate shape also has the meaning that the power line 3-a of the electromagnetic coil 3 can be drawn out. Several holes 4-a are formed in the suction plate 4, as shown in FIG.

Therefore, the suction plate 4 is restricted in the rotational direction with respect to the driven body 6, but is movable in the thrust direction. Suction plate 4
A gap is provided between the yoke and the driven body 6 in the assembled state as shown in FIG. 2, and the suction plate 4 urged by the compression spring 2 is always in contact with the outer peripheral end surface of the yoke. The driven member 6 has a boss portion 6-b formed at the other end to which the driven shaft 7 is fixed. Further, a restoring torque is applied to the driven shaft 7 by a torsion coil spring (not shown) in order to achieve the illustrated phase.

Here, a method for manufacturing the yoke 1 will be described. As mentioned above, since the conventional yoke shape was an integral shape as shown in FIG. 9, the only option was to machine the yoke from a round bar material by lathe processing. However, in this embodiment, the yoke 1 has a cup shape with a thin wall (approximately 0.4 mm), and can be formed by simple deep drawing and pressing as shown in FIG.

FIG. 7 is a process diagram showing the forming process of this yoke 1, and the parts are processed in the process order of (al→mountain)→(C)→(d)→(2) in the figure. Deep drawing is performed in the process of (a)→(bl). In the process of (C), the yoke flange part and the central cylindrical part are trimmed by wobbling processing, and in the process of (d), the outer periphery of the yoke is End face 1-b
In order to form minute grooves in the upper die, the pattern of the die is transferred by a press process using an upper die in which a coining pattern is engraved, and grooves as shown in FIG. 5 are formed. Since these steps are performed by a progressive press machine, the processing cycle time per part is short, and in the case of this embodiment, it takes about 1 second.

Next, the processing steps for the suction plate 4 will be described. The suction plate 4 is processed in the steps shown in FIG. The opposing parts have a concave shape, and the gap δ is defined by the amount of the concavity.In addition, the coining provided on the yoke side is
It is also possible to apply it to the part opposite to -b. Suction plate 4
The degree of consistency required for this is the air gap δ shown in FIG. 3, but since ensuring this accuracy is determined by the precision of the mold, it is easy to manage the degree of glaze for each component. Since these processes are performed using a progressive press machine, the processing cycle time per part is short, and in the case of this example, it takes about 1 second. The operation of the mechanism constructed as described above will be explained. In FIG. 2, the driver 5 is driven in the α direction, and the rotation speed is approximately 1000 rpm.
It is rotating at a speed of m. Further, the yoke 1 fixed thereto and the cylindrical member 2 joined to the yoke 1 are also rotating at the same speed. The electromagnetic coil 3 in the yoke is stationary without being affected by the rotation of the yoke 1, and the power line 3-a is connected to an energization control section (not shown). When the electromagnetic coil 3 is not energized, no electromagnetic action occurs between the yoke 1 and the suction plate 4, and the suction plate 4 is not attracted to the yoke 1. Although a frictional torque due to the weak biasing force of the compression spring 2 is constantly acting on the contact surface between the yoke 1 and the suction plate 4, a restoring torque larger than this frictional torque is applied to the driven shaft 7, so this state does not occur. Therefore, the suction plate 4 will not be moved around by the yoke 1.

Incidentally, in this embodiment, the biasing force of the compression spring 2 is 5 g, f.
, due to this biasing force, the yoke outer peripheral end surface 1-b and the suction plate 4
The frictional torque generated at the contact surface of is approximately 1 gf-am, while the restoring torque applied to the driven shaft 7 is 5 gf-am.
f-cm or more.

When the electromagnetic coil 3 is energized, magnetic lines of force 8 are generated in the magnetic circuit composed of the yoke 1, the attraction plate 4, and the cylindrical member 2, as shown in FIG. ″′C
It will be attracted in the direction shown. As a result, the yoke 1 and the suction plate 4
Frictional force is generated at the contact area A due to adsorption. Drive torque from the yoke 1 is transmitted to the suction plate 4 by this frictional force, and the driven body 6 and driven shaft 7 rotate.

Specifically, this embodiment assumes operation as an intermittent transmission clutch employed in a small printing device, and the angle at which the driven shaft 7 rotates by one energization to the electromagnetic coil 3 is at most 30 degrees. It is degree. That is, after the suction plate 4 is attracted to the yoke 1 by energizing the electromagnetic coil and the driven shaft 7 is driven by a predetermined angle by the power from the driver 5, it is returned to its original phase by the restoring torque of the torsion coil spring mentioned above. In order to return, the power line 3-a of the electromagnetic coil is connected to the suction plate 4 or the driven body 6.
There is no chance of it getting tangled up with anything. Furthermore, this organization
It is necessary to guarantee a durable torque transmission ability as a clutch under usage conditions that require intermittent operation several million times. Therefore, changes in the coefficient of friction between the yoke 1 and the suction plate 4 due to durable wear are not allowed. Outer peripheral end surface 1 of the aforementioned yoke
The groove carved in part 1b retains the lubricating oil to prevent abnormal durability wear due to lack of oil, and on the other hand, by improving the oil film, it prevents contact separation due to the oil film of the lubricating oil on the contact surface that slides at high speed. It also has the effect of preventing the so-called hydroplaning phenomenon.

[Effects of the Invention] As described above, according to the present invention, it is possible to produce a part shape in a short cycle time by using deep drawing processing instead of cutting processing for yoke processing, and it is possible to produce a part shape in a short cycle time. Tool management is simplified because ensuring the sheath degree of the air gap δ does not depend on accuracy control during lathe machining. In addition, on the contact surface between the yoke and the suction plate, grooves with a minute pitch are carved into the yoke or the suction plate by coining, which greatly improves the oil retention effect and prevents reliability from decreasing due to wear. .

Therefore, it is a very effective technique for providing a small electromagnetic clutch with guaranteed durability and reliability at an extremely low cost, and has great technical and industrial significance.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of a small electromagnetic clutch mechanism according to the present invention. FIG. 2 is a cross-sectional view of the same content as FIG. 1. FIG. 3 is a sectional view showing a magnetic circuit portion consisting of a yoke, a suction plate, and a cylindrical member. Figure 4 is a side view with the same content as Figure 3. FIG. 5 is a detailed sectional view of the flange end face of the yoke. FIG. 6 is a diagram showing lines of magnetic force when the electromagnetic coil is energized. Figures 7(a) to (e) are diagrams showing the machining process of the yoke. FIGS. 8(a) to 8(C) are views showing the machining process of the suction plate. FIG. 9 is a diagram explaining the prior art. / Yaw 7 1 −−−−−−−−−−−− Yoke 3・−−−−−
−−−−11 Electromagnetic coil 4 −−−−−−−−1−−−
One suction plate or more

Claims (1)

[Claims] 1) Consisting of a cup-shaped yoke, a suction plate in contact with the opening side of the yoke, and an electromagnetic coil placed in a space formed by the yoke and the suction plate, In an electromagnetic clutch mechanism that transmits power by generating an attractive force between the yoke and the suction plate by energizing a coil,
A compact electromagnetic clutch mechanism characterized by comprising a yoke made of plate-shaped electromagnetic material and formed into a cup shape and a cylindrical part at the center by deep drawing. 2) Consists of a cup-shaped yoke, a suction plate in contact with the opening side of the yoke, and an electromagnetic coil placed in a space formed by the yoke and the suction plate. In an electromagnetic clutch mechanism that generates an attractive force between a yoke and the suction plate to transmit power,
A small electromagnetic clutch comprising a yoke formed by deep drawing a plate-shaped electromagnetic material to form a cup shape and a cylindrical part at the center, and trimming the outer periphery flange and the central cylindrical part. mechanism. 3) Consists of a cup-shaped yoke, a suction plate in contact with the opening side of the yoke, and an electromagnetic coil placed in the space formed by the yoke and the suction plate, and when the electromagnetic coil is energized, In an electromagnetic clutch mechanism in which the yoke generates an adsorption force between the yoke and the suction plate to transmit power, a plate-shaped electromagnetic material is deep-drawn to form a cup shape and its center. A small electromagnetic clutch mechanism characterized by comprising a yoke having a cylindrical part molded into the yoke, and a suction plate having a concave shape facing the yoke and the cylindrical part.