JPS6235533B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electromagnetic clutch disk, and more particularly to an electromagnetic clutch disk suitable for use in an electromagnetic clutch used in a connection between a car cooler compressor and an engine. A conventional electromagnetic clutch for a car cooler is known, for example, from Japanese Patent Application Laid-open No. 50-60654. A disk 240 of this type of rotor is shown in FIG. In the figure, the disk is press-punched from a single steel plate, and consists of a disk plate 241, a disk plate 242, a disk plate 245, four connection parts 246 with a width B radially, and four connection parts 246 with a width C radially. Connecting portion 247, grooves 243, 24
It is formed from 4. In the rotor disk 240 of this conventional type, the magnetic flux φ also flows into the ineffective magnetic paths of the connecting portions 246 and 247, so the effective magnetic flux decreases and the rotor inevitably becomes a large electromagnetic clutch. Ta. In another method, a synthetic resin is filled between the rotor plates as a means of reducing leakage magnetic flux, but this method has drawbacks in terms of reliability under high temperatures and rapid temperature changes. There is also a method, as shown in FIG. 2, in which a plurality of metal pieces made of non-magnetic material are plastically deformed and fixed in grooves formed between the rotor plates. That is, the first disk plate 221 and the second
The disk plates 222 are both metal disks made of magnetic material, and there are respectively
Grooves 221b and 222b are provided. on the other hand,
Three bonded objects 223 made of non-magnetic metal are inserted between the disk plates 221 and 222, and then both end surfaces (upper and lower surfaces in the figure) of the bonded objects 223 are pressed by a press. Pressurize,
It is plastically deformed and fixed in the grooves 221b and 222b. However, as will be described in detail later, this method does not provide sufficient mechanical strength and is mechanically unstable. Furthermore, in these methods, the abnormal high temperature that occurs when the compressor body is locked (the disk 220 is in a stationary state and the rotor 230 is in a rotating state, but the electromagnetic coil 203 is energized in this state. , disk 220 and rotor 2 while maintaining torque transmission ability close to the rated torque.
30 collide violently and the sliding surface reaches 800℃~
The temperature reaches an abnormally high temperature of 900℃. ) cannot be tolerated. In other words, the method of filling with synthetic resin causes thermal deterioration of the resin, while the method shown in Figure 2 lacks sufficient mechanical strength to maintain rotational torque at high temperatures, leading to destruction. . As described above, in the conventional technology, on the one hand, there is a large amount of leakage magnetic flux, and in the other method, it is mechanically unstable, especially at high temperatures. It is an object of the present invention to have a structure that has low leakage magnetic flux and that can mechanically hold against rotational torque by providing a concave and convex portion on the bottom surface of the groove, even at high temperatures.
The point is that it is sufficiently mechanically stabilized. The main point of the present invention is that the inner and outer circumferential surfaces of the disk plates arranged concentrically are opposed to each other with a ring-shaped gap, and that the inner and outer circumferential surfaces have grooves extending over the entire circumference thereof, and furthermore, the inner and outer circumferential surfaces of the disk plates are arranged concentrically. A substantially ring-shaped bonding object made of a non-magnetic material is inserted into a groove formed on each of the inner and outer circumferential surfaces and is surrounded by the disc plate and the mold, and then pressurized with the mold. ,
The purpose of this method is to mechanically fix the disk plates by causing the bonded objects to flow plastically. As a result, the first disk plate 221 and the second disk plate 222 are mechanically integrated interchangeably by the groove, and furthermore, the groove has a structure that can withstand rotational torque due to the uneven portion on the bottom surface of the groove. becomes. Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a partial half cross section of an electromagnetic clutch employing the present invention. The electromagnetic clutch 200 is attached to a car cooler compressor body 200A. The specific configuration is shown below. A boss 211 is fixed to a compressor shaft 210 supported by a bearing 201 with a nut 213, and a disk-shaped disk 220 is formed via a spring 212. The disk 220 adopts the present invention, and as shown in FIG. It is composed of a bonded body 223 made of aluminum, etc.). The rotor 230 is attached to the compressor main body 200A via the bearing 202. rotor 230
According to the present invention, three concentric disks made of magnetic material (steel material), a disk plate 231, a disk plate 232, a disk plate 235,
It is composed of a bonded object 233 and a bonded object 234 made of a non-magnetic material (such as copper). Furthermore, the rotor boss 236 and pulley 237 are connected to the disk plate 23.
5. They are each integrated into the disk plate 231. A belt is engaged with the pulley 237, and the compressor 200A is driven by the automobile engine. The electromagnetic coil 203 is composed of a yoke and a coil, and is directly fixed to the compressor main body 200A. Next, the operation will be explained. When the electromagnetic clutch 200 is not energized, only the rotor 230 driven by the engine via the pulley 237 rotates, and the disk 220 and boss 21 that are separated through the gap rotate.
1. The shaft 210 is stationary. When the electromagnetic coil 203 is energized, the magnetic flux φ flows as shown by the broken line. That is, the yoke of the electromagnetic coil 203 → pulley 237 → disk plate 231 → gap → disk plate 221 → gap → disk plate 2
32 → gap → disk plate 222 → gap → disk plate 235 → rotor boss 236. Due to this magnetic flux φ, the disk 220 is attracted to the rotor 230 and is electromagnetically coupled to rotate. Therefore, the shaft 210 rotates synchronously via the spring 212→boss 211→. Here, each of the coupling members 223, 233, and 234 has sufficient mechanical strength to withstand rotational torque, and at the same time, as mentioned above, is made of a non-magnetic material that does not pass magnetic flux, so magnetic flux leakage occurs. can be minimized. Next, with reference to FIG. 5A and subsequent figures, details of the structure of the coupling portion of the disk plate will be explained. (For simplicity, the description will be given to the disk 220, but it goes without saying that the same applies to the rotor 230.) First, in FIG. 5A, the joint surface of the first disk plate 221 and the second disk plate 222 is Between 221a and 222b there is a width To, a height
A ring-shaped cavity 240 of Ho is interposed. Also,
Grooves 221b and 222b are provided in the direction perpendicular to the surface, respectively. Note that 221c and 222c indicate the end faces of the disk. Next, in FIG. 5B, the groove depth B is determined by the experimental results.
Set to approximately 0.2 to 1.0 mm, preferably 0.2 to 0.5 mm. In addition, the grooves 221b and 222b are provided with uneven portions 221d and 222d on their bottom surfaces to have a structure that can withstand rotational torque. This uneven part 2
21d and 222d are formed on the bottom surface of the grooves 221b and 222b over almost the entire circumference, and generally,
Manufactured by knurling, etc. Also, the average height g of the uneven portions 221d and 222d is
The thickness is preferably about 0.2 to 1.0 mm, preferably about 0.2 to 0.5 mm. Again in FIG. 5A, 223 is a member to be joined, which is more easily plastically deformed than the disk plates 221 and 222, that is, is a joining member made of copper or the like with low deformation resistance, and is ring-shaped and has a cross-sectional width _T1 .
T approximately equal to or slightly smaller than ₀ , height H ₁
is equal to or slightly higher than H ₀ . Even when H ₁ is higher than H ₀ , the difference ΔH is preferably kept as small as possible, for example, about 0.2 to 0.3 mm. The reason for this will be explained later. Further, the cross-sectional shape of the coupling member may be a simple shape such as a round, elliptical or polygonal cross-section in addition to the rectangular cross-section shown in the figure. Since it is plastically deformed after insertion, there is no need to be limited by the shape of the cavity. Further, the groove angle α is a factor that determines the plastic fluidity of the material, and according to experiments, it is desirable that α=25° to 70°. In the joining process, first, as shown in FIG.
1,222 into the ring-shaped cavity 240. Next, as shown in FIG. 7, the whole is placed on the mold 40, and the tip surface 3 whose width is smaller than the cavity width T ₀ is placed on the mold 40.
The connecting member 22 is connected to the pressurizing part 32 of the mold 30 having the
3, the grooves 221b, 222 are formed by plastic deformation.
The combined object 223 is allowed to flow into b. The insertion process shown in FIG. 6 may also be performed using the mold 30. 6th
In the state shown in the figure, the combined object member 223 is attached to the mold 3
Except for the upper and lower end portions corresponding to 0 and 40, it is surrounded by a cavity 240 (or a disk plate), and the height difference ΔH is extremely small. Therefore, it can be said that immediately before pressurization, the entire bonded object is surrounded by the void and the mold. Therefore, as shown in FIG. 7, during pressurization, the coupling member hardly escapes to the outside of the gap, and the grooves 221b, 222b and the concave and convex portions 221d, 222d on the bottom surface are reliably filled. As shown in FIG. 8, the pressurizing protrusion side surface 33 of the mold 30 is inclined by θ with respect to the direction perpendicular to the distal end surface 31 (insertion direction). θ is preferably about 3° to 15°. This means that if θ is small, after joining, the mold 3
This is because 0 becomes difficult to escape. Also, if θ is too large, the direction opposite to the insertion direction of the mold, that is,
The bonded object tends to flow out of the gap, and the insertion depth cannot be increased, making it impossible to generate large internal stress in the bonded object, and thus making it difficult to obtain a large bonding force. As shown in FIG.
In other words, the distance S from the upper end of 22b is as small as possible, in other words, the tip surface 31 is as close as possible to the grooves 221b,
It is desirable to insert it deeply so that it is close to 222b. According to experiments, a highly reliable bonding force can be obtained when the distance S has the following relationship with the width _T0 . O≦S/T ₀ ≦3/4 As a result, friction loss due to plastic flow is reduced, and the bonded object can be sufficiently inserted into the grooves 221b, 222b and the uneven portions 221d, 222d on the bottom surface. FIG. 9 is a diagram showing a state in which the connection is completed.
In the figure, there is a tension force P inside the connected object 223.
acts, and the grooves 221b of the first disk plate 221 and the second disk plate 222,
222b, the bonding surfaces 221a, 222a are firmly spread apart. Here, in order to maintain the configuration as shown in the figure, the material of the first disk plate 221 and the second disk plate 222 must be harder and more rigid than the material of the joining object 223. Because the combined object 22
3 is pressurized by the mold 30 and flows plastically, the first
This is because the disc plate 221 and the second disc plate 222 must be sufficiently rigid without being deformed (although there may be some distortion). In other words, the bonding object 223 must be made of a material that has less deformation resistance than the first disk plate 221 and the second disk plate 222. For example, if the first and second disk plates are made of steel, the joining object may be aluminum,
Brass, copper, etc. are used. The bonded object itself is required to have a certain mechanical strength with respect to shearing, compression, bending, etc.
Needless to say, its size varies depending on the conditions of use of the clutch. Here, in the case of the electromagnetic clutch with the configuration shown in Fig. 3,
The combined bodies 223, 233, and 234 each have a different diameter and may also have different axial heights (outer diameter - inner diameter = ring width: often constant). Now, assuming that the ring width (corresponding to T ₀ in Figure 5) is the same at all three locations and the axial height (H ₀ in Figure 5) is also the same at all three locations, and proceeding with the explanation, we will get the following. Something like this can be said. First, the height H ₀ is determined from the magnetic cross-sectional area of the magnetic circuit, and is approximately a determined value when the performance is the same. Next, as for the ring width T ₀ , the thicker the ring, the larger the machine becomes, and the heavier and more expensive it becomes. On the other hand, as the ring width T ₀ becomes thinner, the effective amount of magnetic flux decreases. These relationships are shown in Figure 10. As a result,
It has become clear that the weight of the electromagnetic clutch is preferably such that T ₀ /H ₀ is 0.3 to 0.6. Generally, if we take a small electromagnetic clutch with a static torque of 3 to 5 kg・m as an example, H ₀ is 4.5 to 5 mm,
Therefore, T ₀ is 1.35 to 3 mm. In the case of the processing method of the present invention, 2.5mm
It is preferable to keep it at a certain level. As described above, by employing the coupling method using the non-magnetic material coupling object according to the present invention, as shown in FIGS. 3 and 4, the rotor 240 is connected using the conventional structure shown in FIG. 1. There are no parts 246 and 247,
Ineffective magnetic flux is eliminated, and with the same weight and size
It is a 1.5 to 1.6 times higher torque machine, and with the same torque, it is 25% smaller and lighter, especially for vehicles.
In terms of weight reduction, it can greatly contribute to reducing fuel consumption. Furthermore, the configuration in which the bottom surface of the groove is provided with uneven portions exhibits an epoch-making effect on rotational torque. This comparison is shown in Table 1.

[Table] In other words, under the abnormally high temperature of 800°C to 900°C that occurs when the compressor body is locked,
For torque torque (applied rated torque),
All of the grooves other than those having uneven portions on the bottom of the groove according to the present invention cannot withstand the problem. This is because the bonded object (such as copper) is dulled at high temperature, internal residual stress is released, and the tension force becomes zero. In contrast, in the present invention, in the case of copper, since it can withstand mechanical shearing force,
It has a yield strength of 2Kg/mm ² at 800℃. Therefore, in this case where unevenness is formed all around the groove bottom, the rated torque of 8.5
It turns out that it has twice the strength. The above explanation has been based on the electromagnetic clutch shown in Fig. 3, but there are cases where the coupling object is located at other than three locations, for example, one location on the rotor side and not on the disk side (single flux type), and one on the rotor side. It goes without saying that it can also be applied to a type with three fluxes and two fluxes on the disk side (triple flux type). Naturally, the present invention also includes a combination of the part having the conventionally known connecting part shown in FIG. 1 and the present invention. For example, the rotor side may have a conventionally known connection part and the disk side may have the present invention, or the reverse configuration may be used. Also included is a portion without unevenness on the bottom surface of the groove and a mixed configuration of the present invention. For example, the disk side may be a smooth portion, and the rotor side may be configured according to the present invention. Next, FIG. 11 shows another embodiment with a different groove shape. That is, in the grooves 221b and 222b,
It has annular ridges 221e, 222e with a height h, the height h is lower than the groove depth B, and the number of the ridges 221e, 222e is preferably 1 to 3. Furthermore, as shown in Fig. 12, this mountain 221e
The grooves are knurled to form uneven portions 221d, and are configured to withstand rotational torque.
Although not shown, the first disk plate 22
An annular ridge 222e of the second disk plate 222 facing the second disk plate 222 is similarly formed with a concave and convex portion 222d. Here, the mountains 221e, 222e
By providing the ridges 221e and 222e, the bonding area of the coupling member 223 increases, and the rotational torque resistance increases by about 1.7 to 2 times. In other words, according to the experimental sample equivalent to Table 1, the weight was 75 kg・m without uneven parts.
High torque can be obtained (at room temperature). Specifically, according to experiments, the relationship between the height h of the projections 221e and 222e and the groove depth B is more desirable than the plastic fluidity of the coupling member 223, as shown by the following relationship. 1/2B≦h≦7/8B FIG. 13 shows a perspective view of the bonded object, which is ring-shaped and has a simple rectangular cross-sectional shape. This bonded object 223 is made of non-magnetic metal, and is processed by cutting pipe material, plastic working, or sintering. FIG. 14, like FIG. 13, shows a perspective view of the bonded object, which is generally ring-shaped with a gap S on the circumference, and has a simple rectangular cross-sectional shape. This bonded object 223 is made of non-magnetic metal, and is made by rolling a wire rod and processing it into a certain size. This gap S has a size such that when the objects 221 and 222 are inserted and pressurized, the objects 221 and 222 are brought into close contact with each other. Specifically, the outer diameter is 54mm, and there is a small gap of about 0.5mm (approximately 1° in angle). As described above, according to the present invention, it is possible to obtain an electromagnetic clutch that has no leakage magnetic flux and is mechanically stable.

[Brief explanation of the drawing]

1 and 2 are external perspective views of a disk of a conventionally known electromagnetic clutch, FIG. 3 is a vertical cross-sectional view of a main part of an electromagnetic clutch according to an embodiment of the present invention, and FIG. External perspective view of disk plate, No. 5A
The figure is a vertical cross-sectional perspective view showing details of the joint portion of the disk plate in the present invention, and FIG. 5B is a view showing details of the groove shape in FIG. 5A. FIGS. 6 to 8 are diagrams showing each step of the bonding method of the present invention, and FIG.
The figure shows the state after the connection is completed. FIG. 10 is a diagram showing the range of T ₀ /H ₀ in the present invention,
1 and 12 are views showing other embodiments of the groove shape in the present invention. FIG. 13 and FIG. 14 are diagrams each showing an example of the combined object. 221... Disc plate, 222... Disc plate, 223... Combined object, 221d...
...Uneven areas.

Claims (1)

[Scope of Claims] 1. A first disk having a portion made of magnetic material and connected to the driving means, and a second disk having a portion made of magnetic material and provided with means for connecting to the driven means. a disk, a means for configuring a magnetic circuit including the first and second disks, and an electromagnetic coil for generating magnetic flux flowing through the magnetic circuit, wherein at least one of the first and second disks In an electromagnetic clutch consisting of a plurality of concentrically arranged disk plates made of magnetic material,
A ring-shaped gap is formed between the inner circumferential surface of the outer disk plate and the outer circumferential surface of the inner disk plate among the disk plates, and an annular groove is provided over the entire circumference of the inner and outer circumferential surfaces. The bottom surface of the groove has a concave and convex portion, and a ring-shaped coupling object made of a non-magnetic metal is located in a space partitioned by the ring-shaped gap, the groove, the concave and convex portion of the groove bottom, and the extension surfaces of the end surfaces of both disk plates. An electromagnetic clutch characterized in that the inner and outer disk plates are connected by the shearing force and tension force of the connecting object. 2. In claim 1, the annular groove has 1 to 3 annular protrusions whose height h is lower than the depth B of the groove, and the protrusions are formed with uneven parts. An electromagnetic clutch featuring