JPH01117164A - Changeover device - Google Patents

Abstract

PURPOSE:To make the positional state of a plunger transferable to a multistage system of more than three stages and thereby simplify its changeover structure by setting up plural pieces of form memory alloy springs in series toward displacement of the plunger, and installing a temperature control means for making each temperature of these springs rise or fall individually. CONSTITUTION:Each temperature of two form memory alloy springs 5 and 5' set up in series toward displacement of a plunger 1 is made to rise or fall individually by temperature rise-fall means (power source) 8, 8'. With this temperature variation, these form memory alloy springs 5, 5' are individually expanded or contracted. A positional state of the plunger is transferred to a multistage system according to a combination of these form memory alloy springs 5, 5' expanded or contacted like this, whereby a position of a selector guide plate in a copying machine is changed over to a state of plural numbers.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a switching device for switching the position of a movably configured member, such as a switching guide plate in a copying machine, into a plurality of states. It is something.

(Prior Art) Conventionally, a solenoid has been used as a switching device to switch the position of a member configured to be movable within a certain range, such as a transport guide plate rotatably attached to a copying machine, into a plurality of states. is the most widely used. This solenoid generally has a structure that attracts a plunger supported in a case by energizing 1i11 stones.For example, in a copying machine, in addition to the guide plate mentioned above,
It is used in a variety of places, such as the switching section for the paper refeed roller to press against and release the paper, the switching section for the paper stop position and paper feeding position of the stopper in the double-sided tray, and the rotation υ control section for the registration roller.

However, even such a solenoid has the following drawbacks.

(1) It is relatively heavy.

(2) If used continuously for a long time, the temperature will rise and the holding power will decrease. Furthermore, even if they are of the continuous use type, their holding power is generally weak.

(3) The impact noise is loud when the plunger sucks.

Therefore, as a switching device to replace such a solenoid,
In recent years, springs that use shape memory alloys whose shape changes with temperature changes have been proposed.

Examples are shown in FIGS. 6(a) and 6(b). In these figures, 101 is a plunger, and this plunger t101 is supported within the case 102 so as to be freely movable in the axial direction, and a fixed flange 103 is integrally formed approximately in the middle thereof. And this fixed 7 lunge 10
A shape memory alloy spring 104 that expands and contracts with temperature changes with a predetermined temperature (transformation point) as a boundary is interposed between one surface of the fixed flange 103 and the inner wall surface of the case 102. and the inner wall surface of the case 102, a bias spring 10 biases the plunger 101 in the direction in which the shape memory alloy spring 104 contracts (leftward in the figure).
5 is interposed.

Figure 5(a) shows the state at low temperature,
At this time, shape memory alloy spring 10 made of shape memory alloy
4 is in a soft and easily deformed state, and the bias spring 105
It is pressed by the urging force of and is in a contracted state. From this state, when the temperature of the shape memory alloy spring 104 is raised to a predetermined temperature or higher by resistance heating, for example by passing a current through both ends of the shape memory alloy spring 104, the shape memory alloy spring 104 becomes bias spring 105. While pushing the fixed flange 103 by overcoming the biasing force, it recovers and stretches to the pre-memorized shape. With this, the 6th
As shown in Figure (b), the plunger 101 protrudes rightward from the case 102, and can be used as a switching device like a conventional solenoid.

According to such a configuration, the disadvantages of using the solenoid described above are eliminated, and the same effects as described above can be obtained with an extremely simple structure.

However, the shape memory alloy that is the material of the shape memory alloy spring 104 generally has only one shape that can be memorized.
Most of the types are unidirectional, so even if the bias spring 105 is used as described above, the position state of the plunger 101 can only be switched in two ways, similar to conventional solenoids. Therefore, in order to apply such a switching device to a structure that switches the position of a member in multiple stages of three or more, it is necessary to use a plurality of switching devices in combination and switch them individually. This has the disadvantage of being complicated and increasing costs.

(Object of the Invention) In view of the above circumstances, the present invention provides a switching device that makes it possible to switch the position state of a plunger in multiple stages of three or more, thereby further simplifying the switching structure of members, etc. The purpose is to provide.

(Structure of the Invention) The present invention includes a plunger that is axially displaceable and biased in one direction, and a shape memory alloy that expands and contracts in the axial direction of the plunger due to temperature changes with a predetermined temperature as a boundary. In the switching device, a plurality of shape memory alloy springs are arranged in series in a direction of displacement of the plunger. At the same time, the shape memory alloy springs are provided with temperature raising/lowering means for raising and lowering the temperature of these shape memory alloy springs individually.

In such a configuration, the temperature of each shape memory alloy spring is individually raised and lowered by the temperature raising/lowering means, and each shape memory alloy spring is expanded and contracted individually, so that the temperature of the plunger is adjusted according to the combination of shape memory alloy springs to be expanded and contracted. The position state can be switched in multiple stages.

(Example) FIGS. 1(a), (b), and (c) show a switching device of the present invention,
In these figures, 1 is a plunger. This plunge 171 is housed in the case 2, and one end thereof is supported by the outer wall of the case 2, and the other end is fitted into the cylindrical part 3 formed in the case 2. It is possible to move in the axial direction while being guided by 3. Further, a fixed flange 4 is integrally formed approximately at the middle portion thereof.

In the figure, between the right side surface of the fixed 7 flange 4 and the right inner wall surface of the case 2, there is 2 g of shape memory alloy! A
Shape memory alloy springs 5 and 5' are interposed in series, and between these shape memory alloy springs 5 and 5' is a material having insulation properties and relatively low thermal conductivity. A movable 7-lunge 6 formed in the shape of a hollow disk is interposed in a state movable in the axial direction of the plunger 1. On the other hand, a bias spring 7 made of a normal metal material is interposed between the left side surface of the fixed flange 4 and the left inner wall surface of the case 2, and the bias spring 7 allows the plunger 1 to be shaped as described above. The memory alloy springs 5, 5' are biased in the direction of contraction, that is, in the right direction in the figure.

The shape memory alloy springs 5, 5' are soft when the temperature is below a predetermined temperature, and therefore easily contract when subjected to an external force, but when heated above a predetermined temperature, the shape memory alloy springs 5, 5' have a predetermined memory. The plunger 1 is configured to extend in the axial direction of the plunger 1 by recovering its original shape. A DC power supply (temperature raising/lowering means>8.8') is connected to both ends of these shape memory alloy springs 5.5' via a switch, and opening and closing of this switch turns the power supply 8.8' on and off. This allows each shape memory alloy spring 5.5' to be individually energized.

In such equipment, each power supply 8.8' is turned off,
When no current is applied to the shape memory alloy springs 5, 5', both of the shape memory alloy springs 5, 5' are at a predetermined temperature or lower, and therefore, as shown in FIG. 1(a), the fixed flange 4
is pressed by the bias spring 7, the shape memory alloy springs 5, 5' contract, and the plunger 1 becomes fully recessed into the case 2.

In such a state, when one of the electric currents 8!8 is turned on and current is passed through only one side of the shape memory alloy spring 5, the temperature of the shape memory alloy spring 5 instantaneously rises due to resistance heating. When this temperature reaches a predetermined temperature, the shape memory alloy spring 5 recovers to its memorized shape and stretches.
The fixed flange 4 is pushed against the biasing force of the bias spring 7, whereby the plunger 1 is in a state in which the case 2 protrudes outward as shown in FIG. 1(b) compared to the state in FIG. 1(a). becomes.

Furthermore, from this state, the other power supply 8' is also switched on,
When a current is applied to the shape memory alloy spring 5' and heated to a predetermined temperature, the fixing 7 flange 4 is further pushed toward the bias spring 7, and the plunger 1 is pushed to its furthest position from the case 2 as shown in FIG. 1(C). It becomes a prominent state.

Therefore, according to this device, the shape memory alloy spring 5 to be heated
．． By selecting the number of 5', the protruding state of the plunger 1 can be switched in three ways. Note that, as shown in this figure, when shape memory alloy springs 5.5' having substantially the same length are used, there are three switching modes.
By using shape memory alloy springs with different lengths, four types of switching can be performed by combining the heated shape memory alloy springs.For example, a shape with equal elongation and a length ratio of 1=2 If a memory alloy spring is used, the amount of protrusion of the plunger 1 can be changed in four ways at approximately equal intervals. Furthermore, if three or more shape memory alloy springs are used, eight or more types of switching are possible. Furthermore, as a modification, the spring used for the bias spring 7 may be made of a shape memory alloy.

Next, an example of a switching structure in which this device is used will be explained below based on FIGS. 2 to 5.

Usage example 1 (Figures 2 and 3 (a) (b) (c)
) The copying machine shown in FIG. 2 is configured to be capable of two-color composite copying and double-sided copying on the same sheet of paper. Specifically, the main body has a contact glass 11 and a document holder 12 on the upper surface, and an optical system 13 and a photoreceptor drum 14 below the main body. It is equipped with a developing device 17, a sub-ring (II device 18, a transfer device 19, a separating device 20, etc.).

The paper transport mechanism includes, in order in the transport direction, a paper feed cassette 21, a paper feed roller 22, a pair of registration rollers 23, a transport belt 24, a pair of fixing rollers 25, a pair of transport rollers 26,
and a pair of discharge rollers 27. Further, an intermediate tray 28 for refeeding paper is provided substantially below the conveyor belt 24, and a stock section 29 for temporarily docking the paper is provided substantially below the ejection roller pair 27. An auxiliary roller 27a that can come into contact with and separate from the upper roller of the pair of discharge rollers 27 is provided at the entrance portion of the discharge roller pair 27.

A switching mechanism 3 is provided upstream of the pair of ejection rollers 27 to switch the paper path to the ejection side, the paper refeeding side, and the stocking side.
0 is provided, and the switching bag W131 of the present invention is used in this switching mechanism 30.

As shown in FIGS. 3(a), 3(b), and 3(c), the switching mechanism 30 includes a switching guide plate 32, a lever 33, and the switching bag! ! 31.

The switching guide plate 32 is configured to be rotatable around a shaft 34, and has a return portion 32a for returning the paper at its rear edge. The lever 33 has one end fixed to the shaft 34 and a long hole 33 at the other end.
a is formed, and the switching device 31 is inserted into this elongated hole 33a.
A protrusion 1a formed on the plunger 1 is fitted therein.

By switching the protruding state of the plunger 1 in the switching mode A1131 into three ways as described above, three paths are formed.

First, the plunger 1 is in the most recessed state (see Figure 1 above).
Corresponding to (a)), as shown in FIG. 3(a), the return section 32a of the switching guide plate 32 creates a return path in which the paper discharged from the pair of transport rollers 26 is directly transported back to the intermediate tray 28 side. is formed. Next, plunger 1
When the switching guide plate 32 protrudes to the intermediate position (corresponding to FIG. 1(b)), as shown in FIG. 3(b), the switching guide plate 32
A discharge path is formed by the upper surface of the conveyance roller pair 26 to directly guide the paper discharged from the conveyance roller pair 26 to the discharge roller pair 27 . Also, plunger 1 is the most protruding! II (1st
(corresponding to FIG. 3(C)), as shown in FIG. 3(C), the conveying roller pair 26 is
A stock path is formed that guides the paper discharged from the storage section 29 to the stock section 29.

In a copying machine having such a configuration, when performing a normal copying operation, the switching mechanism 30 is switched to the ejection state as shown in FIG. 3(b). As a result, the paper fed from the paper feed cassette 21 undergoes transfer on the photosensitive drum 14, is transported by the transport belt 24, is fixed by the fixing roller 25, and then passes through the transport roller pair 26. The paper is directly discharged from the copying machine from the discharge roller pair 27.

Next, when performing two-color development using the main developing device N17 and the sub-developing device II 18, the switching mechanism 30 is switched to the state shown in FIG. 3(a). When paper is fed in the same manner from this state, first, the image developed by the main development process is transferred on the photosensitive drum 14,
After the transferred paper passes through the pair of transport rollers 26, it is guided by the return section 32a and directly transported back to the intermediate tray 28. Then, when the paper is re-fed from the intermediate tray 28, the image developed by the sub-developing device 18 on the photosensitive drum 14 is transferred onto the same side of the paper in an overlapping manner. After this transfer, the paper is similarly discharged from the transport roller pair 26, but at this time, by switching the switching mechanism 30 to the state shown in FIG. 3(b), two-color composite copying is performed on the same side of the paper. It will be discharged in a clean state.

Next, when performing duplex copying on paper, the switching mechanism 30
First, switch to the state shown in FIG. 3(C). In this state, when the transfer is performed in the same manner as described above and the paper is ejected from the pair of transport rollers 26, this paper is guided toward the stock section 29 by the switching guide plate 32, and then Upper roller of roller pair 27 and auxiliary roller 27a
It is temporarily accommodated in the dock section 29 by the following steps.

When the paper is discharged from the stock section 29 again from this state, the paper is reversely conveyed to the intermediate tray 28 in a reversed state from the state in which it was initially fed. and,
When the paper is re-fed from the intermediate tray 28, the transfer will be performed on the back side of the paper, and then by switching the switching mechanism 30 to the state shown in FIG. 3(b), the paper will be copied on both sides. In this state, the paper is discharged from the discharge roller pair 27.

As described above, this copying machine is configured so that both two-color copying and double-sided copying are possible by switching the paper path in three ways on the upstream side of the ejection roller pair 27. When trying to apply a conventional switching device to this copying machine, this conventional switching device can only switch the protrusion state of the plunger in two ways, so in order to obtain the same effect as above, two switching guide plates are required. are provided on the upstream side and on the downstream side, and a switching device is provided individually on each switching guide plate, and the structure is unavoidable in that the paper is distributed in three directions by the combination of switching. On the other hand, if the switching device 31 of the present invention is used, as described above, the paper path can be switched using a single switching guide plate 32 and switching device @ 31, which greatly simplifies the switching structure. can be achieved.

Usage example 2 (Figure 4) Figure 4 shows the automatic document feeder RADF (Ilev).
ersible Auto Document Fee
This figure shows the main part of der). This RADF has a function that automatically feeds and discharges the original onto the contact glass 41, and also automatically turns the original over and feeds it onto the contact glass 41 when double-sided copying of the original is desired. ing.

The switching member 40 shown in this figure is a contact glass 4
It is configured to be freely rotatable about a shaft 42 on the downstream side of 1, and can be switched to three states shown by a solid line 40a and two-dot chain lines 40b and 40c. In the state shown by the solid line 40a, the switching member 40 sends the original sent from above the contact glass 41 back to the contact glass 41 in an upside-down state by guiding it with the curved portion 44, and in the state shown by the two-dot chain line 40b, Its lower end serves as a stopper for the leading edge of the document sent onto the contact glass 41, and in the state of the two-point steel 1140c, the document discharged from the contact glass 41 is stopped by the switching member 41.
, and plays the role of guiding it to a pair of discharge rollers 43.

Since such a switching member 40 also needs to be switched to three states, excellent effects can be obtained by applying the switching device of the present invention to this switching structure in the same manner as the copying machine shown in FIG. 2 above. can be obtained.

Usage Example 3 (Fig. 5) The switching structure shown in Fig. 5 also has the RAD
This structure is provided on the downstream side of F, and is configured so that it can be switched between a mode in which the document is discharged face up and a mode in which the document is discharged face down.

In the same figure, three conveyance rollers 52 are vertically connected to each other in series on the downstream side of the contact glass 51.
a, 52b, 52c are provided, and the conveying roller 52
Document passages 53 and 54 are formed by guide plates between the document passages 52a and 52b and between the transport rollers 52b and 52c, respectively, and a switching guide plate 50 is provided on the downstream side of the document passage 54.

Further, a paper ejection tray 55 and a reverse original ejection passage 56 are provided on the downstream side of the switching guide plate 50, a supply roller pair 57 is provided on the upstream side of this reverse original ejection passage 56, and a paper ejection A paper roller pair 58 is provided respectively. When the original is carried from the supply roller pair 57 to the reverse original ejection passage 56, the original is guided to the reverse original ejection passage 56 and ejected from the ejection roller pair 58. The sheets are stocked in the paper discharge tray 55 in a face-down state compared to the state in which they are sent from the paper discharge tray 51 .

The switching guide plate 50 has a solid line 50a and a two-dot chain line 5.
It has three states shown as 0b and 50c. In the state indicated by the solid line 50a, together with the document paths 53 and 54, the document discharged from between the transport rollers 52b and 52C is configured as a return path for returning between the transport rollers 52a and 52b, and in the state shown by the two-dot chain line 50b, the document path It guides the original ejected from 54 to the reverse original ejection path 56 side, and in the state indicated by the two-dot chain line 50c, guides the original to the ejection tray 55.

With regard to such switching of the switching guide plate 50, the switching structure can be simplified by applying the switching device of the present invention.

(Effects of the Invention) As described above, the present invention arranges a plurality of shape memory alloy springs in series in the direction of displacement of the plunger, lowers the temperature of these shape memory alloy springs individually, and thereby lowers the temperature of each shape memory alloy spring. Since the shape memory alloy spring is made to expand and contract, by appropriately selecting the shape memory alloy spring that expands and contracts in this way, the position state of the plunger can be switched to three or more stages. Therefore, by using such a switching device, it becomes possible to perform multi-step switching of members etc. with a single switching device,
This has the effect of simplifying the switching structure.

[Brief explanation of the drawing]

FIGS. 1(a), (b), and (C) are cross-sectional views of the switching device in position a in an embodiment of the present invention, FIG. 2 is an internal structural diagram of a copying machine to which the switching device is applied, and FIG. ), (b), and (c) are cross-sectional views showing the switching structure of the paper path of the copying machine, FIG. 4 is a cross-sectional view showing the switching structure of the document path of the RADF to which the above switching device is applied, and FIG. Another RAO to which the switching device is applied
Cross-sectional view showing the switching structure of the original path of F, Fig. 6<a) (
b) is a sectional view showing an example of a conventional switching device. DESCRIPTION OF SYMBOLS 1... Plunger, 5, 5'... Shape memory alloy spring, 7... Bias spring, 8.8'... Electric a (temperature reducing means), 31... Switching device. Patent applicant Riyo Mita Agent Co., Ltd.
Patent Attorney Etsushi Kotani Figure 4

Claims (1)

[Claims] 1. A plunger that can be displaced in the axial direction and is biased in one direction, and a shape memory alloy spring that expands and contracts in the axial direction of the plunger due to temperature changes with a predetermined temperature as the boundary. The switching device is configured such that the plunger is displaced to assume a plurality of positions by expansion and contraction of the shape memory alloy spring, wherein a plurality of the shape memory alloy springs are arranged in series in the direction of displacement of the plunger, and A switching device characterized by comprising temperature raising/lowering means for raising and lowering the temperature of these shape memory alloy springs individually. 2. The switching device according to claim 1, wherein each shape memory alloy spring can be individually energized.