JPH089741Y2 - Spring structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a spring structure composed of a stretchable rod and a spring member.

[Conventional technology]

For example, truss type frame structures are generally used in the fields of civil engineering, construction, machinery, and the like. When considering the strength of this truss type frame structure (hereinafter referred to as truss), it is necessary to know the stress of each member constituting the truss. That is, it is necessary to predict how much tensile force or compressive force each member receives when an external force acts on the truss. This prediction is generally made by illustration or calculation.

Truss will be studied in secondary and higher education programs. The learning of the strength calculation is performed by the method using the above-described illustration and calculation. However, since the force is an invisible amount, it is difficult for the learner to intuitively understand the prediction of the member force in the conventional method.

So, as a learning tool for truss, 1-88974
The one shown in the publication is proposed. This is shown in FIG.

In FIG. 16, the warren truss 120 is composed of seven elastic rods 110. The connecting portions (nodes) 111 to 115 of each rod 110 are all formed by pin connection, and each member is rotatable relative to each other. Further, the connecting portions 113 and 115 are fixed on a base (not shown).

The rod 110 is, as shown in FIG. 17, an outer cylinder member 100, 101.
And a spring structure body including both ends of the inner cylinder member 102 slidable by being inserted into the outer cylinder members 100 and 101, and springs 105 and 107 mounted between the both members.

A cap 1 is attached to each of the outer openings of the outer tubular members 100 and 101.
03, 104 are fitted. Flat portions 130 and 131 are formed on the caps 103 and 104, respectively. The flat portions 130 and 131 are provided with holes 103a and 104a, respectively, into which the pins can be inserted.

One end of the spring 105 on the outer cylinder member 100 side is fixed to the end surface of the cap 103, and the other end is fixed to the end surface of the inner cylinder member 102. A rod 106 that extends axially into the inner tubular member 102 is fixed to the cap 104. One end of the spring 107 on the outer cylinder member 101 side is fixed to the tip of this rod 106,
The other end is fixed to the end surface of the inner tubular member 102. Spring 1
In No. 05 and No. 107, the adjacent wire rods are in close contact with each other in the unloaded state, and are installed in the most degenerated state. In addition, on the outer peripheral surface of the central portion of the inner tubular member 102,
A scale for measuring the displacement of the outer tubular member 100, 101 with respect to the inner tubular member 102 is provided.

When an external force is applied to any of the nodes 111 to 115 of the truss 120 (Fig. 16), a tensile force or a compressive force acts on each rod 110 to deform the truss 120. When a tensile force acts on the rod 110, the spring 105 extends and the outer cylinder member 100 slides to the right in FIG. On the other hand, at this time, since the spring 107 cannot be further retracted, the outer cylinder member 101 does not move to the left in the drawing. Therefore, the span 1 increases, which causes the rod 110 to stretch. Also, when a compressive force acts on the rod 110, only the spring 107 expands, so the outer cylinder member 101 moves to the right in the figure, and as a result, the span 1 decreases. As a result, the rod 110 contracts.

In this way, the learner can visually judge what kind of force and how much force acts on the rod 110 constituting each member of the truss, and the learning can be interestingly progressed.

[Problems to be solved by the device]

The conventional spring structure has two springs and two outer cylinder members, respectively. Therefore, the number of parts is increased and the structure is complicated. Further, since the outer cylinder members on both sides slide respectively, there arises a problem that the measurement of the amount of change in the span 1 becomes slightly complicated.

An object of the present invention is to provide a spring structure having a simplified structure and capable of easily measuring the expansion / contraction amount of a rod.

[Means for solving the problem]

The spring structure according to the present invention has an outer tubular member, an inner tubular member, one spring member, and a spring actuation mechanism. The outer tubular member has a first support portion at one end and is open at the other end. The inner tubular member has a second support portion at the other end, and one end is slidably inserted inward from the other end side of the outer tubular member. The spring member is arranged in the inner tubular member. The spring actuating mechanism is configured such that the first support portion of the outer tubular member and the second support portion of the inner tubular member slide toward the first support portion of the spring member when the two tubular members slide in a direction away from each other. A first end portion of the second support portion is fixed to the outer tubular member, a second end portion of the second support portion side is fixed to the inner tubular member, the first support portion and the second support portion. Fixes the first end of the spring member to the inner tubular member and fixes the second end of the spring member to the outer tubular member when the two tubular members slide in directions toward and from each other. .

[Action]

In the spring structure according to the present invention, for example, when an external force acts in the extension direction, the first end of the spring member is fixed to the outer tubular member and the second end of the spring member is placed to the inner tubular member. Since it is fixed, the spring member extends in response to an external force. On the contrary, when an external force acts in the compression direction, contrary to the above, the first end of the spring member is fixed to the inner tubular member and the second end of the spring member is placed against the outer tubular member. Because it is fixed,
As a spring member, it will receive the same force as above,
Grow according to external force.

Here, since there is only one spring member, the number of parts can be reduced and the overall structure can be simplified. Further, even if a force in any direction of a tensile force or a compressive force acts on this spring structure, the spring member is displaced in one direction (tensile direction) with respect to these external forces. Even with respect to external force, the degree of external force can be accurately expressed as a displacement amount with one spring member.

Further, when the present spring structure is used in, for example, a truss frame model, it is possible to easily visually determine whether the member force acting on each spring structure is positive or negative by expanding and contracting the spring structure.

〔Example〕

FIG. 7 shows a truss learning device to which an embodiment of the present invention is applied. This learning device has a truss frame model 50 composed of six members 40 to 45, and a substrate 30 to which the frame model 50 is attached.

The members 40 to 45 constituting the truss frame model 50 have a spring structure as shown in FIG. This spring structure is composed of a stretchable rod member 3 and a spring member 7 provided inside the rod member 3.

The rod 3 has an outer cylinder 1 and an inner cylinder 2 slidable inside the outer cylinder 1. Caps (supporting portions) 4 and 5 are fitted into one end openings of the outer cylinder 1 and the inner cylinder 2, respectively.
Flat portions 4a and 5a are formed on the caps 4 and 5 (FIGS. 8 and 9), and holes 4b and 5b are formed on the flat portions 4a and 5a, respectively.

A rod 6 extending axially to the inside of the inner cylinder 2 is fixed to the cap 4. A pair of claw members 8 are fixed to a substantially central portion of the rod 6 with a predetermined span. The span of each claw member 8 corresponds to the free length of the spring 7. Valve seats 9 and 10 are arranged on the outside of each claw member 8. A hole through which the rod 6 can be inserted is formed in the center of each valve seat 9, 10. The valve seats 9 and 10 are rod 6
It is slidable on the top in the axial direction. Also, the inner cylinder 2
Inside, a bush 2a is fixed between the valve seats 9 and 10. The inner diameter of the bush 2a is smaller than the outer diameters of the valve seats 9 and 10. A spring 7 is mounted in the bush 2a. The inner diameter of the spring 7 is larger than the outer diameter of the claw member 8. Both ends of the spring 7 are seated at 9, 10 respectively.
It is fixed to the end face of.

Thus, the rod 6, the pair of claw members 8, the valve seats 9, 10
A spring operation mechanism is configured by the bush 2a.

Further, the outer cylinder 1 has a distance sensor 11 as shown in FIG.
Is attached. Details of this distance sensor 11
Shown in Figure and Figure 5B. FIG. 5A is a plan view and FIG. 5B is a front view. The distance sensor 11 is a concave case when viewed from the front.
Have twelve. A bar 13 is axially arranged in the recess 12a of the case 12. A slider 14 is slidably provided on the bar 13. A tongue piece 15 having a U-shape in a plan view is provided below the slider 14.
This tongue piece 15 has a leaf spring shape and is always outward (5B
(Downward in the figure). On the other hand, on the bottom wall 12b of the recess 12a, the resistance wire 16 and the extraction electrode 17 are juxtaposed in the longitudinal direction of the bar 13. These resistance wire 16 and extraction electrode 17
The lower part of the tip of the tongue piece 15 is in contact with the upper part. Also the case
Terminals 18, 19, 20 are provided on the lower surface of 12. Terminal 18,2
0 is connected to both ends of the resistance wire 16, and the terminal 19 is connected to the extraction electrode 17.

The connecting portions (nodes) 30 to 33 of the members 40 to 45 shown in FIG. 7 are all smooth nodes. That is, the connecting portions 30 and 31 have a structure as shown in FIG. Figure 8 shows VIII in Figure 7.
-VIII is a schematic cross-sectional view. In FIG. 8, each member 40,4
Holes 4b and 5b in caps 4 and 5 that fit into the ends of 1,44 (Fig. 1)
A bolt 120 is inserted through the flat washer 122a from below. A nut 121 is screwed onto the bolt 120 from above via a plain washer 122b and a spring washer 123. Each member 40,4
Each of the bolts 1,44 is rotatable around the bolt 120. Further, in each connecting portion 30, 31, each bolt 120,
Strings 37 and 38 are wound around each.

Further, the connecting portions 32 and 33 have a structure as shown in FIG. FIG. 9 is a schematic sectional view taken along line IX-IX in FIG.
In FIG. 9, an opening recess 30a is formed on the lower surface of the substrate 30. The bolt 125 is inserted from below into the hole recess 30a. The protrusions of the bolt 125 on the substrate 30 are connected to the spring structures 41, 4 via the collar 127 and the flat washer 128a.
Caps 4 and 5 are fitted to fit the ends of 2,45. A nut 126 is screwed onto the caps 4 and 5 via a plain washer 128b and a spring washer 129. Each of the members 41, 42, 45 is rotatable around the bolt 125. By adjusting the length of the collar 127, the height position of the connecting portions 32, 33 can be adjusted to the height position of the connecting portions 30, 31. As a result, the axes of the members that form the truss are placed in the same plane.

The substrate 30 is a plate made of a transparent resin material such as acrylic resin. Screws 34 to 36 are mounted on the substrate 30. The heads of the screws 34 to 36 are in a state of protruding above the substrate 30.

This learning device has a control device 21 as shown in FIG. In FIG. 6, the control device 21 includes a CPU22 and a ROM2.
It is equipped with a microcomputer consisting of 3 and RAM 24. Further, the control device 21 includes an A / D converter 25, LC
A D (liquid crystal display) 26 and a keyboard 27 are connected. The terminal 19 of the distance sensor 11 is connected to the A / D converter 25. A power supply 28 is connected between the terminals 18 and 20 of the distance sensor 11.

 Next, a method of using this learning tool will be described.

For example, when an external force F acts on the node 30 (FIG. 7), the skeleton model 50 is deformed as shown by the chain line. At this time, the members 40 to 45 respectively expand or contract. Therefore, the learner observes the change in the length of each member 40 to 45,
It is possible to easily visually determine whether the force acting on each member 40 to 45 is a tensile force or a compressive force. The external force F can be loaded by pressing the node 30 directly with a finger or by
This is performed by pulling 37, 38 in an oblique direction and locking one end of the strings 37, 38 with, for example, screws 35b, 36.

Due to the action of the external force F, the member 41 expands to be in the state shown in FIG. That is, in FIG. 2, the outer cylinder 1 and the inner cylinder 2 respectively slide outward. Then, the claw member 8 fixed on the rod 6 moves rightward in FIG. 2 together with the outer cylinder 1, and the claw member 8 moves the valve seat 9 rightward.
Further, the bush 2a moves leftward in the drawing together with the inner cylinder 2, and the end surface of the bush 2a moves the valve seat 10 leftward. Therefore, the valve seats 9 and 10 move away from each other. As a result, the spring 7 whose both end faces are fixed to the valve seats 9 and 10
Expands in accordance with the amount of expansion of the rod 3. Also, the inner cylinder 2
The distance sensor 11 detects the displacement of the outer cylinder 1 with respect to the outer cylinder 1. This displacement amount is converted into a digital amount by the A / D converter 25 (Fig. 6) controlled by the CPU 22, and the LCD2
Displayed in 6. Thereby, the amount of displacement of the inner cylinder 2 with respect to the outer cylinder 1, that is, the amount of elongation of the rod 3 can be measured in real time.

In addition, the member 40 contracts due to the action of the external force F, and the third
The state is as shown in the figure. That is, in FIG. 3, the outer cylinder 1 and the inner cylinder 2 respectively slide inward. Then, the bush 2a moves to the right in FIG. 3 together with the inner cylinder 2, and the end surface of the bush 2a moves the valve seat 9 to the right. Further, the claw member 8 fixed on the rod 6 moves leftward in the drawing together with the outer cylinder 1, and the claw member 8 moves the valve seat 10 leftward. Therefore, the valve seats 9 and 10 move away from each other. As a result, the spring 7 extends in accordance with the amount of contraction of the rod 3. The displacement amount of the outer cylinder 1 with respect to the inner cylinder 2 is detected by the distance sensor 11 in the same manner as described above, and A /
It is displayed on the LCD 26 via the D converter (Fig. 6). Thereby, the displacement amount of the inner cylinder 2 with respect to the outer cylinder 1, that is, the rod 3
The amount of shrinkage of can be measured in real time.

In this embodiment, the spring structure constituting each of the members 40 to 45 has only one outer cylinder and one spring as compared with the conventional one, which can reduce the number of parts of the spring structure itself. The structure can be simplified. Therefore, the overall structure of the truss frame model 50 can be simplified. Also,
The spring 7 extends according to the amount of expansion and contraction of the rod 3 from the unloaded state. Therefore, after unloading the external force F, each member 40-45
Is returned to its original length due to the restoring force of the internal spring 7, whereby the frame model 50 returns to the state before loading. Furthermore, since the inner and outer cylinders are each composed of one member, the rod 3
The amount of expansion and contraction can be easily measured with one distance sensor, and the structure can be further simplified.

Since the substrate 30 is made of transparent resin, the frame model 50 can be enlarged and projected by an OHP (overhead projector), so that many people can study at once.

[Other Examples]

(A) In the above-described embodiment, the so-called tension spring is used as the spring 7 constituting the spring structure, but the present invention can be similarly applied to a compression spring.

FIG. 10 shows a spring structure using this compression spring. In FIG. 10, a rod 53 is constituted by the outer cylinder 51 and the inner cylinder 52. At one end side opening of the outer cylinder 51 and the inner cylinder 52,
Caps 54 and 55 are fitted together, respectively. Cap 54,55
Holes 54a and 55a are formed at the tips of the respective.
At the other end of the inner cylinder 52, a stopper portion 52a is formed which protrudes radially inward and has a hole at the center. A rod 56 extending in the inner cylinder 52 in the axial direction is fixed to the cap 54.

Valve seats 59 and 60 are provided at approximately the center of the rod 56. A hole through which the rod 56 can be inserted is formed in the central portion of the valve seats 59 and 60. The valve seats 59 and 60 are slidable on the rod 56. Further, the span between the valve seats 59 and 60 corresponds to the free length of the spring 57 mounted between the valve seats 59 and 60. Both ends of the spring 57 are fixed to the end faces of the valves 59 and 60, respectively. Claw members 58a, 58b are fixed on the rod 56 outside the valve seats 59, 60. A stopper member 52b is fixed to the inner surface of the inner cylinder 52 corresponding to the mounting position of the claw member 58b. Inner diameter of the stopper portion 52a and stopper member 5
The inner diameter of 2b is larger than the outer diameter of the claw members 58a, 58b, and the valve seat 5
It is smaller than the outer diameter of 9,60. A distance sensor 61 similar to the distance sensor 11 shown in FIGS. 5A and 5B is mounted on the outer cylinder 51. The distance sensor 61 is connected to the same control device as in FIG.

When a tensile force is applied to this spring structure, the outer cylinder 51 and the inner cylinder 52 respectively slide outward as shown in FIG. Then, the stopper portion 52a at the tip of the inner cylinder 52 moves the valve seat 59 leftward in the drawing. Further, the claw member 58b fixed on the rod 56 moves to the right in the figure, and the claw member 58b moves the valve seat 60 to the right. As a result, the spring 57 contracts in correspondence with the amount of expansion of the rod 53.

When a compressive force acts on this spring structure,
As shown in FIG. 12, the outer cylinder 51 and the inner cylinder 52 each slide inward. Then, the stopper member 52b fixed to the inner surface of the inner cylinder 52 moves to the right in the figure, and the stopper member 52b
Moves the valve seat 60 to the right. On the other hand, the claw member 58a fixed on the rod 56 moves leftward in the figure, and the claw member 58a moves the valve seat 59 leftward. As a result, the spring 57 is
Degenerates according to the amount of shrinkage of 53.

Therefore, when this spring structure is applied to a truss learning device, the learner can easily visually determine the positive or negative of the member force acting on each member constituting the truss, as in the above-mentioned embodiment. You can The displacement amount of the inner cylinder 52 with respect to the outer cylinder 51 is detected by the position sensor 61 and displayed on the LCD 26. Thereby, the displacement amount can be measured in real time. Also in this case, as in the above-described embodiment, only one outer cylinder and one spring are required, so that the truss structure can be simplified by reducing the number of parts.

(B) The attachment of the distance sensor 11 is not limited to that shown in FIG. For example, it may be attached as shown in FIG.

In FIG. 13, a distance sensor is attached to the inner cylinder 62 of the spring structure.
11 cases 12 are fixed. The slider 14 of the distance sensor 11 is fixed to the rod 63. Further, a cutout 61a is formed in a portion of the outer cylinder 61 where the distance sensor 11 is attached. The terminals 18 to 20 are connected to the control device 21 (Fig. 6). In this case, the displacement amount of the outer cylinder 61 with respect to the inner cylinder 62 is the inner cylinder 62 of the rod 63 that moves integrally with the outer cylinder 61.
Will be detected as the displacement amount with respect to.

(C) The outer cylinder 1 or the inner cylinder 2 may be provided with a scale so that the distance sensor 11 may be omitted.
In this case, the approximate displacement amount of the outer cylinder 1 with respect to the inner cylinder 2 is visually measured.

(D) The truss frame model of the truss learning device to which the present invention is applied is not limited to that shown in FIG. For example, it can be similarly applied to various trusses such as warren truss, brat truss and how truss. Further, the present invention is not limited to a plane truss, but can be applied to a space truss.

(E) In the above embodiment, the case where the present invention is applied to a truss learning device has been described, but the application of the present invention is not limited to this. For example, it can be used as a stereoscopic sensor as shown in FIG.

The three-dimensional sensor 80 includes a cubic frame structure 90 and a triangular truss attached to the inside of the frame structure 90.
It consists of 70 and. The skeleton structure 90 is composed of, for example, 12 wire rods 91 made of, for example, metal, which are arranged so as to form each ridge of a cube. The wires 91 are rotatably connected to each other by pins 92 to 99.

The triangular truss 70 has a spring structure as shown in FIG.
It is configured by combining 71 to 73 in a triangle. The spring structures 71 to 73 are rotatably connected to each other by pins 74 to 76. Further, each spring structure 71-73 has the same structure as that shown in the above-mentioned embodiment (FIG. 1). A distance sensor 77 is attached to each of the spring structures 71 to 73. This distance sensor 77 has the same structure as that of the above-described embodiment (FIGS. 5A and 5B). Further, the distance sensor 77 is connected to the same control device as in FIG. Each connecting part 74 of this triangular truss 70 ~
The pins 92, 97, 99 of the frame structure 90 are inserted through the 76,
Each is rotatable relative to each other. The inside of the frame structure 90 is filled with, for example, a jelly-like semi-fluid. This prevents impurities from entering the inside of the frame structure 90 from the outside. A cover may be provided around the frame structure 90 instead of filling the semi-fluid.

The three-dimensional sensor 80 is set by embedding it in an object to be measured for strain, for example, concrete of a building or earth and sand. Then, the pins 92 and 98 are fixed to the measurement site in the object to be measured. When an external force acts on the three-dimensional sensor 80 to deform it, the spring structures 71 to 73 forming the triangular truss 70 respectively expand or contract. Then,
The distance sensor 77 detects the amount of expansion and contraction of each spring structure 71-73. This allows the magnitude and direction of the strain inside the concrete to be measured in real time. In addition, when it is embedded in earth and sand, the state of landslides can be observed in real time.

(F) The present invention can be applied to springs only. In this case, it is possible to measure both the tensile load and the compressive load. Moreover, since only one spring is required, the structure can be simplified.

[Effect of device]

In the spring structure according to the present invention, when an external force of tension or compression is applied, the external force can be measured by the extension of one spring member in any case, and the external force can be accurately measured with a simple structure.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a spring structure according to an embodiment of the present invention, FIGS. 2 and 3 are views showing a loaded state of the spring structure, and FIG. 4 is a partially enlarged view of FIG. FIG. 5A is a plan view of a distance sensor, FIG. 5B is a front view thereof, FIG. 6 is a block configuration diagram of a control device, FIG. 7 is a schematic plan view of a learning instrument to which the embodiment is applied, and FIG. 7 is a schematic sectional view taken along the line VIII-VIII of FIG. 7, FIG. 9 is a schematic sectional view taken along the line IX-IX of FIG. 7, and FIG. 10 is a schematic vertical sectional view of a spring structure according to another embodiment of the present invention.
FIGS. 12 and 13 are views showing the loaded state, FIG. 13 is a view showing another mounting state of the distance sensor, and FIG. 14 is a diagram of a triangular truss constituting a three-dimensional sensor to which an embodiment of the present invention is applied. Schematic plan view, FIG. 15 is an overall perspective view of the space truss, 16th
The figure corresponds to Figure 7 of the conventional truss frame model, Figure 17
The drawing is a view corresponding to FIG. 1 of a conventional spring structure. 1 ... Outer cylinder, 2 ... Inner cylinder, 3 ... Rod, 4,5 ... Cap, 6 ...
Rod, 7 ... Spring, 50 ... Truss frame model.

Claims (1)

[Scope of utility model registration request] 1. An outer tubular member having a first support portion at one end and an open other end, and a second support portion at the other end, one end being inside from the other end side of the outer tubular member. An inner tubular member slidably inserted into the inner tubular member, one spring member disposed in the inner tubular member, a first support portion of the outer tubular member and a second support portion of the inner tubular member. Fix the first end portion of the spring member on the side of the first support portion to the outer tubular member when the two tubular members slide in the direction of separating from each other, An end portion is fixed to the inner tubular member, and the first end portion of the spring member is attached to the first end portion of the spring member when the both tubular members slide in a direction in which the first support portion and the second support portion approach each other. A spring actuating mechanism for fixing the second end portion to the outer tubular member while fixing to the inner tubular member; Spring structure with.