JPH03282041A - Reciprocating drive device - Google Patents

Abstract

PURPOSE:To provide reciprocating movement and a neutral state by engaging a pinion gear, revolved around a gear rotated in one direction, alternately with two racks positioned facing each other with a revolution center therebetween. CONSTITUTION:An idler gear 10 for forward is relayed to a gear 9b for forward to effect transmission to a pinion 3 for forward through a gear 5, and the gear 3 is collided with a rack 1 for forward. In this case, the rack 1 is located in a position where it is not engaged with a pinion gear 4 for reverse. When a rack table continues forward movement and the gear 3 is moved to the end surface of the rack 1, the gear is separated away from the rack, and a pinion is started to revolve. Revolution is continued until the pinion 4 is collided with a rack 2 for reverse having tooth surface positioned facing that of other rack with a revolution center therebetween. When the pinion is collided with the rack 2 as a result of revolution of the pinion 4, forward and reverse linear movement of a rack table 23 are practicable. By energizing a solenoid 36 before shift from forward (reverse) to reverse (forward), a rotary sheet metal 21 is locked, and a neutral state is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drive device that uses a unidirectional rotational drive source to reciprocate and stop a load.

(Prior Art) Examples of conventionally reciprocating loads include the document table and mirror table of a copying machine. The driving of the document table and mirror table requires constant speed forward motion and reciprocating motion of backward and slow motion in synchronization with the drive of the main body such as the image carrier and the conveyance roller. The drive device to achieve this uses a unidirectional motor that also serves as the main body drive as the drive source, transmits the drive forward and backward, two spring clutches to disconnect the ignition, and a solenoid for switching. A mechanism combining one or two gears and a gear train was used.

(Problems to be Solved by the Invention) However, spring clutches and solenoids have the following problems.

A reciprocating drive device that does not use solenoids has been desired.

(1) The spring clutch itself has many parts, and if the precision of each part varies, phenomena such as strange noises, slipping, spring breakage, and twisting occur.

Therefore, it was difficult to manage the precision of each component.

(2) Because the volume and weight of the spring clutch (so-called a block of iron) is large, especially in small copying machines,
This increases the space of the entire drive device, which is contrary to the desire to miniaturize the device.

Furthermore, the heavy use of precision parts makes the device expensive, which is contrary to the aim of not only miniaturizing the device but also making the device inexpensive.

(3) In addition, when applied to drive the document table of a copying machine, etc., it is necessary not only to perform reciprocating motion but also to be able to maintain a neutral state in order to match the timing with process conditions such as charging, transfer, and fixing. .

A simple mechanism that does not use a spring clutch was desired.

(Normally, a solenoid is used for the actuator that converts electrical input into mechanical output, but TsureMade generates a sudden shock when activated, so it is desirable to have a mechanism that uses the smallest possible solenoid to achieve a neutral state.) Ta.

However, the driving gears are always subject to reaction force from the load, and in order to bring the engaged gears into a neutral state, actuators and actuators that generate an acting force greater than the reaction force are required. .

The present invention has been made to solve the above problems, and its objectives are as follows: 1. To provide a reciprocating drive device that can achieve reciprocating motion and a neutral state without using a clutch or a large solenoid. It is in.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a pinion gear that meshes with a gear that rotates in one direction and is supported so as to be able to revolve while rotating, and a center of revolution of the pinion gear. A drive device is provided with two racks facing each other with a pinion gear and two racks disposed in between, and the pinion gear and the two racks perform reciprocating motion by meshing alternately by the revolving motion of the pinion gear, and the pinion gear and the rack A neutral mechanism that prevents the pinion gear from rotating at both ends of the rack where the rack is disengaged, and a control circuit that operates the neutral mechanism, and when the rack changes from forward movement to backward movement or backward movement. It is configured to be in a neutral state when switching from forward motion to forward motion.

(Function) In the present invention, a pinion gear that revolves around a gear that rotates in one direction alternately meshes with two racks that face each other with the center of revolution in between. You can perform back and forth repetitive movements without using.

Moreover, since the pinion gear is configured to stop its revolution before it meshes with either of the two racks (at the time of reciprocating M#Jv'J#!!), the reaction force caused by the meshing of the pinion gear and rack gear is reduced. I don't accept it.

r-sensardine 4a4) The present invention will be explained below based on illustrated embodiments.

1 to 12 show embodiments of the present invention, taking an example of a document table driving device of a copying machine. Figure FJ1 shows a state in which the rack stand 23, which is a component of the document table, is moving linearly in the forward direction, and its cross section along line CC is shown in FIG. Figure 2 shows a state in which the rack stand 23 is moving straight &1 in the backward direction, and its E-E cross section is the 6th
As shown in the figure. 3 and 4 show the neutral state. 7 to PJI9 are schematic explanatory diagrams showing the positional relationship between the pinion gear and the rack.

Generally, the components of the document table of a copying machine include a document table glass, a document pressure plate for holding down the document, and a rack gear, and are positioned on the side plate of the main body via rails so as to be capable of reciprocating linear movement. The rack stand 23 of the six embodiments, in which the original table moves linearly when the rack engages with a rotationally moving pinion gear, has two racks: a forward rack 1 and a reverse rack 2.
Is it because of the book rack? The south sides face each other. A pinion gear rotating in one direction between the two racks revolves around the shaft 12 and engages the two racks alternately, repeating back and forth reciprocating motion, moving the document table back and forth. In order to change the speed, 3 forward pinions and 4 reverse pinions with different rotational speeds are arranged in parallel. When moving forward, the forward pinion gear 3 engages with the forward rack l, as shown in Figure 1, and when moving backward, the As shown in FIG. 2, a reverse pinion gear 4 is configured to mesh with a reverse rack 2. Let me explain how it works.

The forward pinion 3 and the reverse pinion 4 are rotationally fitted to a shaft 16 fixed to a rotary sheet metal 21 that is rotatably supported via bearings 19 and 20 about the shaft 12 . Therefore, the forward and reverse pinions can revolve around the shaft 12. The shaft 12 is rotatably supported by a side plate 25 and a support plate 22 via bearings 19 and 20. axis 12
A gear 5 is rotatably fitted to the holder, and a gear 6.7 is fixed to the holder.

The forward pinion meshes with gear 5, and the VK forward pinion 4 meshes with gear 6.

When the gear of gear 5.6 rotates clockwise, the pinion gear rotates. At that time, the pinion gear tries to revolve clockwise once through the plate metal that rotates once due to the rotational moment due to the pressure applied to the meshing tooth surfaces.In order to reliably obtain the moment force, the pinion gear A friction resistance member is sandwiched between 21 and 21.

The gear train during forward movement will be explained with reference to Figures 1 and 5. The drive gear 9 uses a two-stage gear with a different number of teeth in order to change the rack speed between the forward drive 7b and the reverse drive 9a, and is fixed to the output shaft 15 of a motor 11 fixed to a side plate and rotating in one direction. ing. 0 is transmitted to the forward pinion 3 via the gear 5 via the forward idler gear lO to the forward gear 9b.
The direction of rotation is as shown in Figure 1. The forward pinion gear 3 hits the forward rack 1 due to the moment force of the above-mentioned revolution, and at this time, the forward rack 1 is in a position where it does not mesh with the reverse pinion gear 4. When the forward pinion gear 3 meshes with the rack, a load from the rack is applied to the meshing tooth surface, which acts in the direction of the gear's pressure angle of 0. The angle A between the center of rotation of the forward pinion 3 and the straight line connecting the center of revolution and the rack l is the angle B when the center of revolution is placed on the straight line that indicates the direction of the engagement pressure angle between the rack and pinion (Fig. 7). ) to 90 degrees as shown in Figure 8, the moment acts on the pinion gear when it bites in the direction in which it engages with the rack, so once it engages with the rack, it will not escape and will transmit the drive reliably. be done.

In this state, forward linear movement of the rack base is possible. When the rack base continues to move forward and the pinion gear 3 reaches the end face of the rack l, it leaves the rack and the pinion begins to revolve as described above. The revolution continues until the reverse pinion 4 abuts against the reverse rack 2 whose tooth surfaces face each other with the center of revolution in between. At this time, the backward rack 2 is shifted by a distance sufficient to collide with the forward rack 1.

FIG. 2 and FIG. 6 are explanatory diagrams showing the reverse state, in which the reverse pinion gear 4 uses the reverse gear 9a of the drive gear 9 as a drive source, relays the reverse idle gear 8, The signal is transmitted to a gear 7 fixed to the same axis, and rotates via a gear 6 fixed coaxially.

The rotation direction is as shown. When the reversing pinion 4 hits the reversing rack 2 as it revolves, the pinion gear bites into the rack and is placed in the same way as when moving forward, so the rack base 23 can move backward linearly in this state. . At this time, the forward pinion 3 is in a position where it does not mesh with the reverse rack 2. When the rack base continues its backward motion and the reverse pinion gear 4 reaches the end face of the reverse rack 2 and leaves the rack, the pinion begins to revolve one clockwise direction. Then, the revolution continues until the forward pinion 3 meshes with the forward rack l, and the rack table switches to forward motion.

The gear specifications in this embodiment are summarized in table ff11.

Nod below. If the rotation speed of the drive gear 9 is 30 rpm, the forward rack speed is 20.1 (increase/5 ec), the reverse rack speed is 40.2 (ms/5 ec), and the You can change the round trip speed.

Next, the neutral state for cutting off power transmission will be explained with reference to FIGS. 3 and 4. In FIG. 3, the rotary plate 21 is locked by energizing the solenoid 36 before switching from the reverse state to the forward state, and in FIG. 4, the rotating plate 21 is locked by energizing the solenoid 36 before switching from the forward state to the reverse state. The rotating sheet metal 21 is locked and is in a neutral state.

The slide lever 37 is always urged by the spring 39 and abuts against the locking pin 40. The slide lever 37 is loosely fitted into the guide 38 and is attached to be movable in the left-right direction. The tip of the slide lever 37 is a small solenoid 36
When the solenoid 36 is engaged and the solenoid 36 is energized, the lever 37 moves to the right against the force of the spring 39. Guide 38. The solenoid 36 is fixed to a drive side plate (not shown).

The right tip of the slide lever 37 is close to the rotating metal plate 21, and when the solenoid 36 is energized, the right tip of the slide lever 37 moves to a position where it can come into contact with the center shaft 35a or the pin 35b.

The central shaft 35a protrudes from the rotary sheet metal 21 by a length sufficient to come into contact with the slide lever 37, and the pin 35b is provided at a position symmetrical to the pin 35a with the shaft 12 as the center. Turn on solenoid 36.

The conditions for turning OFF vary depending on the specifications and configuration of the copying machine, but the following cases are usually considered. In other words, the light source (
In particular, if the start-up time of a fluorescent light is long, the fuser has a long startup time, one sheet is not fed correctly, or the timing of high-voltage transfer, charging, etc. is not correct, This is a case where time is required for body cleaning, etc.

Therefore, the document table operates according to the sequence shown in FIG. 1O.

In the above explanation, two racks are arranged in vertically related positions, and the lever that locks the sheet metal for one turn and makes the neutral state is a slide lever. In Figures 11 and 12, two racks are placed in the front and rear relative positions, creating a neutral state! I will explain the lever used with Nagi using a rotating lever.

Figure 11 is an explanatory plan view with the FFI advancing rack on the front side, the reverse rack on the back side, and the south side facing inside.
FIG. 2 is an explanatory partial cross-sectional view thereof.

The forward rack 69 and the reverse rack 70 are connected to the forward pinion gear 54. The tooth surfaces are directed inward with a reverse pinion gear 56 in between. The racks 69, 70 are attached to a rack stand (not shown), and each has a forward pinion gear 54. When the reverse pinion gear 56 is engaged, the rack base moves forward or backward. When the rotating state (movement) is changed from the forward state (motion) to the backward state (motion), the rotating movement 8-64 activated by a solenoid 67, which will be described later, prevents the rotating sheet metal 50 from rotating, resulting in a neutral state. The upper end of the shaft 52 (revolution center axis) is rotatably supported by a bearing 61,
The lower end of the shaft 52 is rotatably supported by a bearing (none of which is shown).The shaft 52 is rotated in one direction by a gear (not shown), and the gear 51 is rotated clockwise (clockwise) via a pin 71. (Fig. 11). The gear 53 (for backward movement) idles relative to the shaft 52 and is rotated clockwise (FIG. 11) by a gear (not shown). The pinion shaft 55 is fixed perpendicularly to the rotating sheet metal 50.

Forward pinion gear 54. A reverse pinion gear 56 is attached to the pinion shaft 55. Reverse pinion gear 56
A friction pad 57 is in sliding contact with the side surface of the thrust presser 58 . A constant pressure is applied by a spring 59. Therefore, when the gear 53 rotates, the reverse pinion gear 56 also rotates, a frictional load is generated on the side surface of the gear 56, and a rotational force is always generated in the rotating sheet metal 50 in the clockwise direction.

The rotating lever 64 is loosely fitted into a pin 65 implanted in the side plate 66, and is biased counterclockwise by a spring (not shown). Bending portion 50a.

An elongated hole 64a is provided at the center lower end of the 0-turn lever 64, which is set by a solenoid 67 to have two state positions: a position where it can come into contact with the lever 50b (two-dot chain line), and a non-contact position m (solid line). A solenoid operating pin 68 is loosely fitted into the elongated hole 64a. Therefore, when the solenoid 67 is turned on, the rotating lever 64 rotates clockwise to stop the rotation of the sheet metal 50 for one rotation, and the rack base becomes in the neutral state.

When the solenoid 67 is turned off, the rotating lever 64 rotates counterclockwise, and the rotating sheet metal 50 rotates approximately 90 degrees.
The rack stand moves backward or forward. The movement of the rack base is carried out in accordance with the sequence shown in FIG. 1O, as in the previous embodiment.

In the above explanation, we used a two-stage pinion gear to change forward and reverse speeds, but if you want to make forward and reverse speeds constant,
Only one pinion gear is required, and two rack gears can be arranged on the same plane, making the configuration simpler.

In this embodiment, the reciprocating motion of the document table of a copying machine is particularly taken as an example, but it goes without saying that the present invention can also be applied to other reciprocating motion devices such as a scanner of a printer.

(Effects of the Invention) The present invention has the above-described configuration and operation, and can perform reciprocating motion without using a spring clutch or large solenoid that requires precision parts, and can be brought into a neutral state when switching between reciprocating motions. When applied to a document table of a copying machine, the copying machine can be made smaller and lower in price.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, in which the rack stand of the document table is moving linearly in the forward direction, and Fig. 2 is an explanatory diagram of the state in which the rack stand of the document table is linearly moving in the backward direction. 3 and 4 are explanatory diagrams of the neutral state. Figure 5 is a sectional view taken along line C-C in Figure 1, and Figure 6 is a cross-sectional view taken along line E-- in Figure 2.
E sectional view. Figures w47 to g59 are explanatory diagrams of the positional relationship between the rack and the binion. FIG. 10 shows the sequence of movements of the document table. FIG. 11 and FIG. 12 are plan explanatory views of other embodiments. It is a partial sectional explanatory view. Explanation of symbols l... Forward rack 2... Reverse rack 3.
... Forward pinion gear 4... Reverse pinion gear 5... Forward gear 6... Reverse gear 11.
... Main motor 12 ... Revolution center axis 67 ... Solenoid 69
...Forward rack 7o...Backward rack Fig. 3 Fig. 4 Fig. 7 Fig. 4

Claims (1)

[Claims] A pinion gear that meshes with a gear that rotates in one direction and is supported so as to be able to revolve while rotating on its own axis, and two racks facing each other with the center of revolution of the pinion gear in between are provided. and two racks that perform reciprocating motion by being alternately engaged with each other by the revolving motion of a pinion gear; It is characterized by comprising a neutral mechanism that prevents the rack from moving forward, and a control circuit that activates the neutral mechanism, and that the rack enters a neutral state when the forward movement of the rack is changed to the backward movement or when the backward movement is changed to the forward movement. Reciprocating drive device.