JPS6244133B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a spring joint used as a universal joint that swingably connects two members.

(Prior Art) Such a spring joint is used to connect members that rotate at high speed, such as a flywheel or a gyro rotor, so as to be swingable in all directions.
That is, it is used, for example, to elastically couple a gyro rotor to a drive shaft so that the rotor can tilt in any direction. In this case, the gimbal body is coupled to the drive shaft by two spring joints coaxial with the first gimbal shaft, and to the gyroscope rotor by two spring joints coaxial with the second gimbal shaft. The gimbal axis is perpendicular to the second gimbal axis and the drive axis. The member fixed to the gyro rotor or the gyro and the member fixed to the drive shaft can be formed by providing holes and slits in a single material along with a leaf spring that connects them. For example, U.S. Pat.
No. 3575475 shows a spring joint of this type. In this spring joint, the apertures have a circular cross section and four elastic connections are formed by providing four apertures in a single piece of material. Two groups of these four apertures are provided, the axis of each group being parallel to one of the transverse axes of the spring joint, and each aperture is a square quadruple hole.
They are arranged to form two corners. The apertures are also interconnected via bent slots in the material. A leaf spring is thus formed in said material, the faces of which are constituted in part by the wall surrounding the aperture and in part by the wall surrounding the bent slot. There is. The two leaf springs constituting one elastic joint cross each other, and the midpoint of each leaf spring coincides with the midpoint of the square. The leaf spring is thickest in this part, and the main axis of the elastic joint also passes through this part. The leaf spring is thinnest on both sides of this pivot axis.
The leaf spring forms an arc shape from this thinnest position, and
connected to one main body. The diameters of these four apertures are determined by the length of the leaf spring. The larger the diameter of the aperture, the larger the size and weight of the intermediate section must be. Since this leaf spring has great flexibility only at its thinnest position, it has the disadvantage that the spring as a whole has a relatively high rigidity. however,
These disadvantages, on the other hand, lead to the advantage that leaf springs have high compressive, tensile and breaking strengths in the longitudinal direction and high shear strengths in the cross-sectional direction.

Universal joint type spring joints are also known in which two bodies are swingably connected by alternating leaf springs having a uniform width and thickness over the entire length. Although such leaf springs are easier to fabricate than the leaf springs of comparable size, they lack longitudinal compressive, tensile, and breaking strength, and have low cross-sectional shear strength.

The present invention provides a spring joint that has both the advantages of a type of leaf spring formed by a plurality of interconnected apertures and the advantages of a type of leaf spring having a uniform width and thickness over its entire length. The purpose is to provide the following. Thereby, the length of the intersecting leaf springs, the size of the aperture, and the size of the main body connected by the leaf springs can be made extremely small. When the spring joint according to the invention is used for driving a gyroscope rotor, the gimbal body becomes compact for a given length of the mutually intersecting leaf springs, so that the dimensions of the rotor are reduced for the same supporting force of the spring joint. You will be able to get a large amount.

This invention can produce excellent effects for the reasons listed below.

1. Balance can be easily achieved by downsizing the gimbal body (middle part).

2 Grooves provided in spring joints have a pumping effect that generates a disturbance moment due to gas turbulence and friction, but this disturbance moment can be significantly reduced by reducing the cross-sectional area of the groove formed by the opening. It will be done.

3. Since only a small amount of material is cut to form the grooves, the balance of the rotating mass can be precisely controlled. Dynamic adjustment is also easy.

4. By reducing the cross-section of the groove, the stability of the body penetrated by this aperture is increased and uniformity of the flexibility of the spring joint consisting of intersecting leaf springs is easily obtained. .

5. The overall structure of the joint can be made smaller.

The above-mentioned object is achieved in a spring joint as described above by shaping the leaf spring in such a way that the radius of curvature forming its concave surface is larger than the maximum size of the aperture. That is, the above-mentioned object is a spring joint for swingably connecting two members, which has a plurality of pairs of leaf springs in which each pair of leaf springs crosses each other, and the leaf springs are made of a single material. is formed integrally with the two members and connected to the members by a curved concave surface having a relatively small radius of curvature at both ends thereof, and further in these members, each aperture is connected to the other three apertures. four parallel apertures of non-circular cross section are provided closer to the two apertures in the apertures, such that the portion between these apertures forms a leaf spring; In a spring joint, the end of each leaf spring that is connected to the member through a curved surface is separated from the other end by a connecting portion having a length sufficiently large compared to the thickness. , is achieved by a spring joint characterized in that the connecting part has a concave surface with a radius of curvature larger than the maximum lateral dimension of the aperture.

A single leaf spring is used to swingably connect the two members to each other, both ends of the leaf spring are connected to the member with a curved concave surface, and the leaf spring is integrally formed with the member. The spring joint is configured such that two parallel apertures extend through the member from one end face to the other end face and are complementary in shape to each other by slits, the apertures having a non-circular aperture and a non-circular aperture. A technique for the replacement is proposed in German Patent Application No. 2525530, page 39, lines 17 to 26. However, this proposal does not provide any details regarding the shape of this non-circular aperture.

It has also been proposed to form these holes by electrical discharge machining. Electric discharge machining can also be used in the present invention. In this case, it is preferable to use a wire longer than the entire length of the opening as the discharge electrode. The use of wire for electrical discharge machining is not new.

The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

The spring joint shown in FIGS. 1 and 2 connects two coaxial ring bodies 20 and 22 having the same outer diameter. These ring bodies 20 and 2
2 are spaced apart from each other by a small distance 24, and are connected to each other by leaf springs 26 and 28 which intersect with each other in a criss-cross pattern. Therefore, these two ring bodies 20 and 2
2 are swingable about a common axis 30. These ring bodies have a coaxial cylindrical outer peripheral surface 32,
34, end faces 36, 38 perpendicular to the axis 30, a large diameter arc 40 with a cross section of 200° and a small diameter arc 42 with a cross section of 160°, and a portion 4 connecting the ends of the two arcs;
Each has an inner circumferential surface consisting of 4.
Therefore, the radial thickness of each arc 40 portion of the ring body is smaller than the radial thickness of the arc 42 portion. This thicker cross-sectional portion of each ring has a thin cylindrical projection 46, which
protrudes inside the opponent's ring body and its outer surface 3
It has the same height as 6 or 38. Two cross-shaped leaf springs 26 and 28 are each arranged diametrically of the ring body. The lower leaf spring 26 projects from the inner surface 43 with a section formed as an arc 42 and has a projection of the upper ring body 20 below the central plane 48 of the space delimited by the spacing 24 between the two ring bodies. It is connected to 46. The upper leaf spring 28 projects from the inner surface 45 of the ring body 20 above the central plane 48 and is connected to the protrusion 46 of the opposing ring body 22 . The hatched cross-section of the spring in FIG. 2 shows the central portion of each leaf spring.

The parts constituted by the ring bodies 20 and 22 and the leaf springs 26 and 28 are made of one piece of material. This is manufactured as follows. That is, a cylinder with end faces 36 and 38 is cut with four parallel apertures extending from face 36 of the cylindrical material to opposite face 38, the longitudinal axis A of which As shown in the figure, it is parallel to the axis 30 of the cylinder and forms four corners of a quadrilateral. Each of the apertures is thus adjacent to two other apertures.

In this above-described embodiment, the four apertures have the same cross-section. This cross section has a circular arc whose center of curvature coincides with the axis 30, and leaf springs 26 and 28.
and two generally radial arcs that coincide with the concave surface of. These three arcs also have three corners. These corners are rounded.

The cylinder having two end faces 36 and 38 is further provided with two rings 20 and 2 having a spacing 24 from each other.
A deep groove is formed forming the inner end of 2. Furthermore, a groove 50 is cut in the end face 36 parallel to the arc 45, and this groove 50 reaches and connects the groove 24. This arcuate groove 50 reaches from one portion 44 to the other portion 44 .
A similar arcuate groove 52 is cut into the end face 38. This groove 52 is also connected to the ring groove 24 in the same way. Furthermore, a groove 5 perpendicular to the cross section
4 is cut from the material at right angles to the axis 30, so that the longitudinal axis 56 of the groove 54 intersects the axis 30 in the plane 48.

The leaf spring 28 extends from the end face 36 of the material to the ring body 2.
It is provided by cutting or other methods up to the inner end surface of 0. Similarly, the leaf spring 26 extends from the end face 38 to the ring 2.
It is provided by removing up to the inner end surface of 2. This leaves only leaf spring 26 in ring 22 and only leaf spring 28 in ring 20. The two leaf springs are separated by a groove 54 and intersect each other at right angles.

Finally, the protrusion 4 protruding from the ring
6 must be separated from the other rings. This is not completely achieved by the arcuately curved grooves 50, 52. Axis 3 for complete separation
An internal groove 58 parallel to 0 is provided in the rings 20, 22, and the section 44 is formed by the shape of two opposing grooves.

The two rings 20 and 22 are therefore only connected by two mutually intersecting leaf springs 26 and 28.

A major feature of the above-described spring joint according to the present invention lies in the concavely curved surfaces of the leaf springs 26, 28 defined by the apertures, which
It is thinnest on both sides 60 of 0 and has a curvature R across the longest transverse length of each of the apertures. In the embodiment shown in FIG. 1, the radius of curvature R of the concavely curved upper surface of the leaf spring 26 is
is approximately 2 sides of the triangular arc seen in the cross section of the aperture.
It has twice the length. When the aperture has a circular cross section, as in conventional spring joints,
The radius of curvature R is only half the diameter of the aperture.

By increasing the radius of curvature R, the thickness of the leaf spring gradually increases from the thinnest position 60 at first, and then rapidly increases. In this way, properties such as very high stiffness of the overall joint, low structural mass and appropriate stresses are satisfied while maintaining a certain springiness.

The radius of curvature R, the width and the minimum thickness of the two leaf springs are best chosen such that the radial shear load is the same as the fracture strength. This gives the leaf spring maximum load carrying capacity.

When a relative pitching moment with a vector component in the direction of the axis 30 and a component perpendicular thereto acts on the two rings 20 and 22, the leaf spring bends under the influence of the first component and bends around the axis 30. allows elastic and relative rotation of the two rings 20 and 22. However, the other component of the vector elicits a very high resistance in the leaf spring.
In the structure according to the invention having four apertures passing through the above-described member, the spring joint is much more flexible and bendable than a member consisting of apertures of the same size and circular cross-section. It is.

3, 4 and 5, a gimbal spring joint is shown which is used with one end connected to a gyro rotor of a gyro device and the other end connected to a drive shaft. This spring joint has the shape of a hollow cylinder with two parallel end faces 70 and 72;
This joint is made by slits and grooves on the circumference
divided into two parts. First portion 74 has an end surface 70, second portion 76 has an end surface 72, and a third portion 78 exists between the two portions. This third portion 78 constitutes a gimbal member, and is swingable together with the first portion 74 around the gimbal axis 84 and swingable around the gimbal axis 82 together with the second portion 76. be. This 2
Two gimbal axes 82 and 84 are arranged diametrically across the joint and intersect the cylindrical joint axis 80. Gimbal axis 82 is perpendicular to axes 80 and 84.

Two spring joints with intersecting leaf springs as described in FIGS. 1 and 2 are coaxial about axis 82 and form a single gimbal joint. Two further spring joints are coaxial with shaft 84 and constitute another gimbal joint.

The three parts 74, 76 and 78 are connected to each other by four pairs of leaf springs and are completely separated by the previously mentioned slits. The slits include slits 86 and 88 parallel to the end faces 70 and 72.
and slits 90 and 92 parallel to axis 80 and perpendicular to gimbal axis 84 or 82, and slits 94 parallel to end faces 70 and 72.
It is. These slits connect to grooves parallel to the cardan axes 82 and 84, which limit the leaf spring pairs.

Also, in the spring joint of FIGS. 1 and 2, the two leaf springs 26 and 28 are separated in the center by a diametrically running groove 54 as shown in FIGS. The crossed leaf springs are 4
separated by two apertures 96. This opening 96
is parallel to axis 80 and intersects gimbal axes 82 and 84.

The configuration shown in FIGS. 3 to 5 is essentially different from the prior art configuration of US Pat. No. 3,575,475 in the shape of the aperture that restricts the leaf spring. Although this prior art configuration has a circular cross section,
The configuration of this embodiment has a non-circular shape as shown in the embodiment of FIGS. 1 and 2.

As in the prior art, the leaf springs are partially in a plane containing the gimbal axes 82, 84 and partially perpendicular to this plane.

However, great benefits can be obtained if the individual leaf springs form a large angle, for example 45 DEG, with respect to a plane 98 (FIG. 4) containing the two gimbal axes 82 and 84. This is illustrated in the embodiment of FIG. 7, shown corresponding to the center of FIG. are doing. These parts are connected to each other only by intersecting leaf springs, the others being connected to each other by slits 86 to 86.
92.

When used for driving a gyro rotor, part 78 constitutes a gimbal part, which part 78 is fixed to the drive shaft by means of two mutually coaxial leaf spring joints and to two other mutually It is connected to a fixed portion 74 of the gyro rotor by a coaxial gimbal joint, thus making the gyro rotor swingable in all directions but fixed against relative rotation.

In contrast to the embodiments shown in FIGS. 3-5, the embodiment shown in FIG. 7 has the advantage that a favorable symmetry is achieved.

Another embodiment is shown in FIG. 6, and this figure also shows a portion of the developed view of the hollow cylinder, similar to FIG. 7. The embodiment of FIG. 7 differs from the embodiment of FIGS. 3 to 5 only in the shape of the leaf spring. Since the four apertures are restricted by each pair of leaf springs, they have slightly different cross-sectional shapes. This aperture has substantially straight outer parts 100 and 2.
It has two curved sides 102 and 104. The thinnest part 106 of the leaf spring is therefore approximately equidistant from the intersection point 108 and the part 110 where the leaf spring is connected to the body. The thinnest portion 106 is also located further away from the intersection of the leaf springs than in the embodiment of FIGS. 3-5.

In the embodiments described above, the leaf springs intersect at right angles, but it is also possible to form grooves in which the two leaf springs intersect at an angle other than 90°. This is illustrated in the embodiment shown in FIG. In this embodiment, the shapes of the left and right grooves are different from the shapes of the upper and lower grooves. Also, the thinnest part of the leaf spring is located much closer to the intersection point of the leaf spring than the location where the leaf spring is connected to the main body.

The gimbal spring joints shown in Figures 3 to 5 are 4
It has pairs of intersecting leaf springs, each pair of leaf springs being defined by four parallel apertures passing through the circumferential surface of the ring-shaped body from the inside to the outside. . Each of these four openings is the same as the opening in FIG. 1, and the midpoint A of the opening forming the corner of the square in FIG. 1 is set as the midpoint of each of the openings.

Modern electrical discharge machining techniques can be used to form this aperture. This process can be carried out by means of a stretched wire, which passes through an opening in the cylindrical body parallel to the spring axis.
It can be moved on a trajectory corresponding to the shape of the aperture.
The wire cuts the core out of the hollow cylindrical shape, and its removal leaves behind an aperture.

Two pairs of intersecting leaf springs are provided along each of the two gimbal axes 82 and 84 shown in FIG. 3, with each pair of leaf springs being defined by a group of four apertures. However, the four apertures in each group are exactly opposite the four apertures in the other group. The processing wire is part 74, 7
6 and 78, and the wire is passed through the hollow cylinder parallel to the gimbal axis. During processing, the wire is
Guided along the triangular shape of the aperture, two mutually opposing cores are excised. For example, when the wire is moved parallel to the gimbal 82, the cutouts are present on the left and right sides of the gimbal axis. The apertures remaining after resection of the core are exactly opposite each other. Formation of the apertures is also very easy.

The electrodes shown in FIGS. 9-11 may also be used in manufacturing the gimbal spring joints of FIGS. 3-5 using electrical discharge machining techniques. In this case, for the manufacture of each pair of leaf springs that intersect with each other, the external electrodes 11
2 and internal electrode 114 are used. This external electrode 112 is a conductive member having parallel prismatic feature pins 116 and 118 near its ends. The length of the pin of this electrode corresponds to the width of each leaf spring and is increased by the spacing of the leaf springs that intersect with each other. The sides of the pins 116 and 118 facing each other are shown in FIG. 11 in a cross-section of the two pins 116 and 118 across the electrode 112. This shape is configured such that the space 120 between the two pins has a cross-sectional shape that corresponds to the longitudinal transverse direction of each leaf spring. Internal electrode 114
has two pins 120 and 122, the opposite sides of which are parallel to the internal electrodes. In other respects, the cross-sectional shape and length are the same as pins 116 and 118.

In order to carry out the electrical discharge machining process, two electrodes 1
12 and 114 are placed in the positions shown in FIGS. 9 and 10. Electrode 114 is inserted inside the ring-shaped body parallel to its axis. The two pins 120 and 122 are then aligned with the cross-section in which the gimbal axis is to be located. There is an electrode 1 on the outside of the ring-shaped body.
12 is positioned parallel to electrode 114, and its pins 116 and 118 pass through a plane containing the Cardan axis. The two electrodes 112 and 114 are pushed out in the radial direction, which is the direction of the arrow. This takes place in an electrode cell, with an electric current being applied by suitable means. Pins 116 and 118 enter the workpiece from the outside and pins 120 and 122 from the inside, while the intersecting leaf springs are separated from each other by apertures 96 as already described in the embodiment of FIG. . two electrodes 112 and 11
By returning to the position shown in FIGS. 9 and 10 in the direction opposite to the arrow 4, a pair of leaf springs is formed. The workpiece is then rotated 90 degrees about axis 80 relative to electrodes 112 and 114 to form the next pair of intersecting leaf springs. After the four pairs of leaf springs are formed, the workpiece is quickly processed.

In the embodiment of FIG. 7, the electrode pin 116
The positions ˜122 are made different from the other embodiments.

According to the above-described manufacturing method, accurate alignment of the spring surfaces of the gimbal axis is guaranteed. Therefore, it is possible to avoid stiffening of the spring due to bending or misalignment of the groups of four grooves facing each other.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment to which a spring joint according to the present invention is applied, in which two cylindrical bodies are swingably connected by the spring joint so that their swing axes coincide with each other. 2 is a bottom view taken from the direction of arrow 1 in FIG. 2, FIG. 2 is a cross-sectional view taken from line 2-2 in FIG. 1, and FIG. 3 is partially taken from the arrow in FIG. 4 is a front view of a gimbal spring joint made up of three parts for driving a gyroscope, taken in cross section from the 3-3 plane of FIG. 5
The figure is a developed view of the circumferential surface of the gimbal spring joint in Figures 4 and 5, and Figure 6 corresponds to the central part of Figure 5, and the angular position of the leaf spring is as shown in Figures 3 to 5. Figure 7 is a developed view of the gimbal spring joint, which is different from the
Figure 6 is a developed view of a gimbal spring joint with the same part as that of the leaf springs, but the shape of the leaf springs is different. 10, a front view of a three-part cylindrical gimbaled spring joint corresponding to FIG. 1
0 is a side view of the gimbal spring joint with the aforementioned electrical means, showing a partial cross-section taken along line 10--10 of FIG. 9, and FIG. 11 is a side view taken along line 10--10 of FIG. 11 is a cross-sectional view of the electrode as seen from No. 11. 20, 22... Ring body, 26, 28... Leaf spring, 30... Drive shaft, 32, 34... Outer peripheral surface of ring body, 74, 76, 78... Each part of the gimbal device.

Claims (1)

[Claims] 1. A spring joint for swingably connecting two members, the spring joint having a plurality of pairs of leaf springs in which each pair of leaf springs crosses each other, and the leaf springs are connected to a single leaf spring. a material formed integrally with the two members and connected to the members by a curved concave surface having a relatively small radius of curvature at both ends; providing parallel apertures, each of the four apertures being located closer to the other two apertures than one of the other three apertures; The portion of the member between these apertures forms the leaf spring, and the end of each leaf spring that joins the member via the curved surface is in contact with the other end in thickness. a spring joint separated by connecting portions having a length sufficiently greater than the width of the opening; A spring joint characterized by: 2. The gimbal body is coupled to the gyro rotor by a first pair of coaxial elastic coupling parts, and
It is connected to the drive shaft by a pair of coaxial elastic coupling parts, the longitudinal axes of the two pairs of elastic coupling parts constitute a gimbal axis perpendicular to each other, and the gimbal body, the gyro rotor, and the drive shaft are made of a single material. A universal spring joint for a gyroscope formed by being divided by a slit formed in the gyroscope, wherein each of the elastic coupling portions is a spring joint according to claim 1. Universal spring fitting for scopes. 3. The spring joint according to claim 2, wherein each of the leaf springs has the same angle with respect to the plane formed by the two gimbal axes in order to obtain symmetrical characteristics. 4. The spring joint according to claim 2 or 3, wherein the intersecting angle of the leaf spring is an angle other than 90° in order to obtain uniform flexibility against shear force. .