JPH0129720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a balance weight guide device in a parallel ruler device.

The main object of the present invention is to provide a parallel ruler device that includes:
Magnets are placed on the bottom side of the weight insertion space formed in the vertical rail and on the opposite side of the balance weight, which can run freely, so that the same polar surfaces face each other, and the balance weight is influenced by the magnetic force of the magnets. Therefore, in a device that is floated relative to the bottom surface of a weight insertion space, the floating distance of the balance weight relative to the bottom surface is prevented from changing significantly due to a change in the load of the balance weight in a downward vertical direction relative to the bottom surface. It is.

In the parallel ruler device, the downward vertical load of the balance weight on the bottom surface of the weight insertion space changes every time the inclination angle of the drawing board changes. Therefore, when the balance weight is levitated by magnetic force against the bottom surface of the weight insertion space to lighten its movement, when the downward vertical load of the balance weight on the bottom surface of the weight insertion space changes, both The distance between the balance weight and the bottom surface of the weight insertion space changes greatly due to the magnetic force acting therebetween. Therefore,
When the balance weight changes up and down in this way, a drawback arises in that the storage space for the balance weight formed in the vertical rail must be widened. Therefore, the present invention provides a balance weight and a portion facing the bottom side of the weight insertion space.
The above-mentioned defect is attempted to be solved by arranging a plurality of magnetic pole tracks in parallel. This is due to the following reasons.

As shown in FIG. 4, if the width and magnetic force of each of the magnets 2 and 4 are constant, the vertical axis is the repulsive force, and the horizontal axis is the gap between the opposing magnets 2 and 4, then the magnets 2 are arranged in 8 rows relative to each other. Different poles are arranged in parallel so that they are adjacent to each other,
When the magnets 4 are arranged in eight rows in parallel so that different poles are adjacent to each other, and the magnets 2 and 4 are arranged with the same poles facing each other, the gap-repulsive force characteristic is shown by curve 6. 8 is a characteristic curve for 6 columns, 10 is a characteristic curve for 4 columns, and 12 is a characteristic curve for 2 columns.

As is clear from the above characteristic diagram, as the number of rows of magnets increases and the number of magnetic poles increases, the curve of the characteristic curve becomes steeper. That is, although the repulsive force is large, the attenuation of the repulsive force is also significant as the gap widens. This means that when a predetermined load is applied downward to the magnet 2 to the extent that the magnet 2 does not touch the magnet 4, when this load is changed in a direction to reduce the load, the gap between the magnet 2 and the magnet 4 changes. reaches the conclusion that the larger the number of rows of magnets 2 and 4, the smaller the number of rows.

This conclusion can also be drawn from the magnetic flux density distribution characteristic diagrams showing the test results using a Gaussmeter shown in FIGS. 5 to 8, in which the width and magnetic force of each magnet were kept constant. In the figure, the horizontal axis indicates the width of the magnet,
The vertical axis indicates the magnetic flux density, and the number 015678 attached to the characteristic curve indicates the distance from the magnetic pole surface. Figure 5 shows the characteristics when the magnets are arranged in two rows in parallel so that different poles are adjacent to each other, Figure 6 shows the characteristics when the magnets are arranged in four rows, and Figure 7 shows the characteristics when the magnets are arranged in four rows. A characteristic diagram of magnets arranged in six rows is shown, and FIG. 8 shows a characteristic diagram of magnets arranged in eight rows.
As is clear from this figure, the magnet density attenuates as it moves away from the magnetic pole face, and the magnet density attenuates more markedly when there are many rows of magnets than when there are fewer rows of magnets. Therefore,
If the number of rows of magnets is increased, if one of the magnets is levitated relative to the other magnet by repulsive magnetic force, when the load applied to one of the magnets towards the other magnet changes from the maximum value to the minimum value. , in order to reduce the change in the opposing gap between the pair of magnets, it is sufficient to increase the number of rows of magnets in parallel.

The present invention is based on the above idea, and the configuration of the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

Reference numeral 2 denotes a drawing board, which is fixed to the drawing board support frame of the drafting table so that it can be set at a desired inclination angle between a horizontal state and a substantially vertical standing state. 4 and 6 are drawing board 2
A weight insertion space 8 and a groove are formed in the vertical rails 4 and 6 over the entire length in the longitudinal direction. In the groove on the top side of the vertical rail, a magnet 10 consisting of four magnetic rubbers is installed along the entire length of the rail.
are arranged in parallel so that different poles are adjacent to each other,
Four magnetic pole tracks of SNSN are formed on the upper surface of each of the vertical rails 4 and 6 by the magnetic rubber. Magnets 12 and 14, each made of two magnetic rubbers, are fitted into the grooves on the bottom side of the vertical rail so that different polarities are adjacent to each other.
A pair of two NS magnetic pole tracks are formed at a predetermined interval on the bottom surface of the NS. Reference numeral 16 denotes a magnet consisting of four magnetic rubbers that are fitted and fixed in parallel in a groove formed on the lower surface of the upper horizontal part of the vertical cursor 18 so that different polarities are adjacent to each other.
The vertical cursor 18 is levitated relative to the vertical rail 4 due to the repulsive magnetic force acting between the magnets 10 and 10 .
The magnets 16, 10, 12, 14 are attached to band-shaped iron pieces 20, 2 placed on the bottom of the groove in which they fit.
It is adsorbed to 2, 24, and 26. Reference numeral 28 denotes two guide rollers for preventing lateral vibration that are rotatably supported on the lower horizontal portion of the vertical cursor 18, and these surfaces are connected to a pair of vertical rails formed on the bottom wall of the vertical rail 4. It is in rotatable contact with one of the rail surfaces. One guide roller (not shown) for preventing lateral vibration, which is rotatably supported by the lower horizontal portion of the vertical cursor 4, is rotatably abutted on the other of the vertical rail surfaces. One end of each wire rope 30, 32 is connected to the front and rear ends of the upper horizontal portion of the vertical cursor 4, and the wire ropes 30, 32 are connected to rope pulleys 34, 36 rotatably disposed at both ends of the vertical rail 4. It is spread over. 38 is a balance weight disposed within the weight insertion space 8, and the other ends of the wire ropes 30, 32 are connected to the front and rear ends of this balance weight. Reference numerals 40 and 42 designate magnets consisting of a pair of magnetic rubbers fixed to both sides of the lower surface of the balance weight 38, respectively.The magnet 40 has the same polarity facing the magnet 12, and the magnet 42 has the same polarity facing the magnet 12. The homopolar plane faces 14. Due to the repulsive magnetic force moving between the magnets 40 and 12 and between 42 and 14, the balance weight 38 floats a predetermined distance from the bottom surface of the weight insertion space 8. Reference numeral 44 designates a pair of guide rollers for preventing lateral vibration that are rotatably supported on the lower surface of the balance weight 38, and these surfaces are formed along the entire length of the bottom wall of the vertical rail 4 in its longitudinal direction. A balance weight 38 is rotatably abutted on one of the pair of vertical rail surfaces, and a balance weight 38 is positioned between the pair of guide rollers and rotates on the lower surface of the balance weight 38 on the other surface of the vertical rail surface. The surfaces of freely supported guide rollers (not shown) are in contact with each other. 4
6 is a ruler mounting plate formed integrally with the vertical cursor 18, and between this and a regular mounting plate 48 formed integrally with the vertical cursor 50 movably arranged along the vertical rail 6. A horizontal ruler 52 is removably hung on the frame. As shown in FIG. 3, mounting screws 54 are fixedly installed near both ends of the horizontal ruler 52, washers 56 are fitted onto the mounting screws 54, and moldings 58 are screwed together. 60 is the mounting screw 5
This is a cap screw screwed onto the upper end of 4 to prevent the molding from coming off. Both ends of the horizontal ruler 52 are attached to the mounting plate 46,
48 and the mounting screw 54 to the mounting plate 46,
48 into the vertically elongated holes 62, 64, and then rotate the molding 58 in the tightening direction to tighten the horizontal ruler 52.
Both ends of the ruler are fixed to ruler mounting plates 46 and 48. The lower surface of the horizontal ruler 52 is set to be slightly raised relative to the two surfaces of the drawing board. A balance weight (not shown) is also arranged on the vertical rail 6, and the configuration of the balance weight, vertical rail 6, and vertical cursor 50 is exactly the same as that of the balance weight 38, vertical rail 4, and vertical cursor 18. .

The total weight of the horizontal ruler 52 and the vertical cursors 18, 50, and the balance weight 38 on the vertical rails 4, 6 side
The total weight is set to be the same.

Next, the operation of this embodiment will be explained.

Normally, this type of parallel ruler device is used with the drawing board 2 standing vertically. When the drawing board 2 is raised up, the horizontal ruler 52 tries to fall along the drawing board 2 surface, but this falling force is due to the falling force of the two balance weights 38 (one not shown). Even if the horizontal ruler 52 is offset and the hand is released from the horizontal ruler 52, the horizontal ruler 52 remains at a desired position. When a force is applied to the horizontal ruler 52 or the vertical cursors 18, 50 in the vertical direction in FIG. The two balance weights 38 move vertically in conjunction with the vertical cursors 18, 50.
It moves in a floating state while being guided by the vertical rail surfaces of the vertical rails 4 and 6 in the opposite direction. As described above, since the vertical cursors 18, 50 and the balance weight 38 are suspended by magnetic force relative to the travel path, the horizontal ruler 52 can be moved smoothly with extremely light manual operation force. When the drawing board 2 is tilted from a horizontal state to an upright direction at, for example, 80 degrees with respect to the floor surface, the balance weight 38 is closer to the bottom surface of the weight insertion space 8 than when the drawing board 2 is in a horizontal state. The downward vertical load is greatly reduced. However, the opposing distances between the magnets 40 and 12 and between the magnets 42 and 14 do not widen significantly as the load is reduced, and the changes are slight. This is because each magnetic pole surface of the magnets 40, 12, 42, and 14 is constituted by a plurality of rows of magnetic pole tracks. Therefore, since the rise and fall of the balance weight 38 due to changes in the inclination of the drawing board 2 are minute, there is no need to take up a large space in the weight insertion space 8.

Since the present invention is configured as described above, the vertical width of the weight insertion space can be reduced, and the vertical rail can be made smaller and lighter.

[Brief explanation of drawings]

Figure 1 is a partial side sectional view, Figure 2 is an overall plan view, Figure 3 is a cross-sectional view, Figure 4 is a gap-repulsion characteristic diagram of the magnets, and Figure 5 is the magnetic flux in the case of two magnets. Density distribution characteristic diagram, Figure 6 is a magnetic flux density distribution characteristic diagram for the case of 4 magnets, Figure 7 is the magnetic flux density distribution characteristic diagram for the case of 6 magnets, Figure 8 is the magnetic flux density distribution characteristic diagram for the case of 8 magnets. It is a characteristic diagram. 2... Drawing board, 4, 6... Vertical rail, 8... Weight insertion space, 10... Magnet, 12, 14...
Magnet, 16... Magnet, 18... Vertical cursor, 2
0, 22, 24, 26... Iron piece, 28... Guide roller, 30, 32... Wire rope, 34, 36
...Rope pulley, 38...Balance weight,
40, 42...Magnet, 44...Guide roller, 4
6, 48...Ruler mounting plate, 50...Vertical cursor,
52... Horizontal ruler, 66... Horizontal ruler, 68... Guide rail, 70, 72... Magnetic rubber, 7
4...Horizontal cursor, 76, 78...Magnetic rubber.

Claims (1)

[Claims] 1 Vertical rails 4, 6 arranged on the side of the drawing board 2
, a balance weight 38 movably disposed within a weight insertion space 8 formed over substantially the entire length of the vertical rails 4, 6;
vertical rails 4,
Vertical cursors 18, 50 that are successively moved in opposite directions along 6;
50, in a parallel ruler device comprising a horizontal ruler 52 attached at right angles to the vertical rails 4 and 6, a plurality of rows of mutually different poles are arranged on the bottom side of the weight insertion space 8 without any gaps; Adjacent magnetic pole tracks are arranged in parallel so that the direction of their rows is parallel to the longitudinal direction of the vertical rails 4 and 6, while on the balance weight 38 side, the same poles as the magnetic pole tracks are opposite to each other. The weight of the balance weight 38 is reduced by the repulsive magnetic force acting between the mutually opposing magnetic pole tracks on the bottom side of the weight insertion space 8 and the balance weight 38 side. A balance weight guide device characterized in that it supports a load in a downward direction substantially perpendicular to the bottom of a weight insertion space 8.