WO2003076830A1

WO2003076830A1 - Driven/driving piece assembly with a fixed cycle and non-constant speed ratio through a cycle

Info

Publication number: WO2003076830A1
Application number: PCT/FR2003/000666
Authority: WO
Inventors: Laurent Giacomuzzi
Original assignee: Egides
Priority date: 2002-03-08
Filing date: 2003-02-28
Publication date: 2003-09-18
Also published as: EP1483518A1; FR2836971A1; FR2836971B1; AU2003229849A1

Abstract

The transmission means between the first moving piece (1) and the second moving piece (2) comprise a guide (7), defining a first cam profile (7a) and a rigid connection (4) of the rod-type, which connects the first moving piece (1) to the second moving piece (2) such that the distance between the two moving pieces is variable. Said connection (4) is displaced in a permanently guided manner by the first profile of the cam (7a) and cooperates with a second cam profile (21a) on the second moving piece (2) for the transmission of movement between the two moving pieces, the two cam profiles (7a, 21a) being chosen such that the speed ratio between the two moving pieces (1 and 2) varies through the course of a cycle.

Description

FIXED CYCLE DRIVING MOBILE / DRIVEN MOBILE ASSEMBLY WITH NON-CONSTANT SPEED RATIO DURING A CYCLE

The present invention relates to a driving mobile / driven mobile assembly, comprising transmission means which make it possible to ensure a transmission of movement between the driving mobile and the driven mobile according to a fixed cycle during which the gear ratio between the two mobile n is not constant. The invention finds its application in all industrial equipment comprising a member (mobile driven) to be driven by a fixed cycle, with a variable speed of movement during a cycle, such as for example, and in a nonlimiting manner , manipulator arm, indexed transfer system, turntable, ...

In the present text, “guided mobile” means any guided mobile, and in particular any mechanical member, part or assembly of parts, which is driven by an actuator, whatever the type of actuator and whatever the movement (linear , rotary, ...) of the mobile. The actuator can be automatic (motor, pneumatic cylinder, ...) or manual (lever, manually actuated arm).

In the present text, "guided mobile" means any guided mobile, and in particular any part or assembly of parts, which is driven by the driving mobile, via the rigid link, whatever the movement (linear, rotary, etc. ) of the driven mobile. In this text, “canned cycle” means any cycle composed of a predefined and fixed sequence of movement phases and possibly stop phases, as opposed to cycles which are automatically modified by external data, such as by example of the variable cycles which are a function of the state of the environment of the driven mobile, said state being measured by one or more sensors, or even such as for example cycles programmable.

The main objective of the present invention is to provide a simple, reliable and low cost solution for driving a mobile (mobile driven) at variable speed and according to a fixed and repetitive cycle, and which in a manner general allows to respect the following conditions: a) A positioning of the driven mobile which is precise during the whole cycle, and which is reproducible with precision from one cycle to another, b) A linear speed profile of the driven mobile on a cycle which is not constant, and which is reproducible with precision from one cycle to another. More particularly, when the cycle comprises at least one phase of stopping the driven mobile, the solution of the invention must make it possible to obtain: c) stopping the driven mobile with a precise and reproducible positioning from one cycle to the other, and in particular a more precise positioning than that which would be obtained by simply suspending the control of an actuator driving the driven mobile, on a state of a sensor detecting the stop position of the driven mobile, d) maintaining each stop position, which ^'may be the external stresses (latch stop position). The above objectives are achieved by the invention by means of an assembly which is known in that it comprises a first mobile and a second mobile, and transmission means allowing a transmission of movement between the two mobiles according to a canned cycle during which the speed ratio between the two mobiles is not constant, one of the mobiles being a driving mobile, the other mobile being a driven mobile. Characteristically according to the invention, said transmission means comprise a guide separate from the two mobiles and defining a first cam profile, and a rigid connection which connects the first mobile to the second mobile so that the distance between the two mobile leading and led is variable; the first mobile comprises a guide portion which forms a second cam profile, and said rigid connection on the one hand is held in abutment on the first cam profile so that during movement of the first mobile the rigid connection is moved while being permanently guided by the first cam profile, and on the other hand cooperates with the second cam profile of the second mobile for the transmission of movement between the two mobile; the two cam profiles are chosen so that the speed ratio between the two moving and driving moving parts during a cycle is not constant. More particularly, that at least a portion of the first cam profile is oriented in the same direction as the second cam profile so that the second mobile is immobilized when the rigid connection is guided by said portion.

Preferably, the assembly further comprises a compression-expansion unit which connects the first mobile and said connection, said a recession-expansion unit being designed to be compressed when the first mobile approaches the second mobile, and for relax during the acceleration phases of the second mobile relative to the first mobile. Other characteristics and advantages of the invention will appear more clearly on reading the description below of several alternative embodiments of the invention, which description is given by way of nonlimiting example and with reference to the accompanying drawings on which: - Figures 1 to 7 show different positions during a cycle of a moving mobile / driven mobile assembly produced in accordance with a first variant of the invention, FIGS. 8 to 12 represent different positions during a cycle of a movable driving / driven mobile assembly produced in accordance with second variant of the invention, FIGS. 13 to 17 represent different positions during a cycle of a driving mobile / driven mobile assembly produced in accordance with the third variant of the invention, FIG. 18 and a rear view of the driving mobile / driven mobile assembly of FIGS. 13 to 17. FIGS. 19 to 22 represent different positions during a cycle of a movable driving / driven mobile assembly produced in accordance with a fourth variant of the invention, FIGS. 23 to 22 26 represent different positions during a cycle of a mobile driving / mobile driven assembly produced in accordance with a fifth variant of the invention, FIG. 27 represents a mobile driving / mobile driven assembly conforming to a sixth var iante of the invention.

There is shown in Figure 1 a first alternative embodiment of a movable assembly 1 / driven mobile 2 of the invention. In this variant embodiment, the driving mobile 1 essentially comprises a part 10 threaded and mounted sliding on a rectilinear guide 3. This part 10 is coupled to an actuator

(not shown) such as for example a linear cylinder or equivalent, which makes it possible to move it in translation, by sliding it along the guide 3. The driven mobile 2 is constituted by a part 20, which is also threaded on the straight guide 3, and which can freely slide in translation relative to this guide 3. In this alternative embodiment, the two moving leads 1 and driven 2 are therefore designed to move linearly in the same direction, corresponding to axis AA, of guide 3.

More particularly, the part 20 comprises a rectilinear oblong lumen 21, the general direction of which makes substantially an angle α with the direction of movement of the part 20. Equivalently, this lumen 21 could be replaced by a groove of the same geometry.

The part 10 and the part 20 are mechanically connected to each other by a connecting rod 4. This connecting rod 4 is in the form of a rod (or arm) 4a of which a first end is pivotally mounted relative to the part 10 along an axis 5, transverse to the direction of movement of the part 10; the rod 4 is extended at its other end by a transverse cylindrical pin 4b. One end of this crank pin 4b of the rod 4 is passed through the lumen 21 of the part 20, and can move exclusively in translation inside this lumen 21. In the alternative embodiment of FIG. 1, between the piece 10 and the link 4 is also mounted a compression-expansion unit 6. More particularly, in the example illustrated, this compression-expansion unit 6 comprises a tubular body 6a inside which is mounted a spring (not visible in the figures) and a rod 6b, one part of which is slidably mounted inside the tubular part 6a, and the lower end of which is pivotally mounted relative to the rod 4. When the rod 4 pivots upwards according to the axis 5, relative to the part 10, the rod 6b rises inside the tubular part 6a and compresses the spring housed inside the tubular part 6a.

In addition to the above elements, the whole of the invention comprises also a guide 7 in the form of a plate whose upper edge 7a extends parallel along the guide 3, that is to say along the path of the driving mobile 1 and the driven mobile 2. The crank pin 4b of the link 4 is permanently maintained in simple support on the upper edge 7a of the guide, which upper edge 7a defines a first cam profile for the link 4, the internal face 21 has light 21 of the part 20 defining a second cam profile for the rod 4.

At the start of an operating cycle, the driving mobile 1 is in a position such that the part 10 is in abutment in contact with the curved part 7b (FIG. 1) of the guide 7. This initial position is not shown on the attached figures. During an operating cycle, the part 10 of the driving mobile 1 is initially (“outward” path) pushed in translation by the actuator along the guide 3 (FIG. 1 / arrow D). The end of this “outward” path of the driving mobile corresponds to the position of the part 10 in abutment against the curved part 7c of the guide 7 (FIG. 1). In a second step (“return” path), the part 10 of the driving mobile 1 is pulled by the above-mentioned actuator so as to move in the opposite direction (FIG. 1 / arrow D '), to return to the above-mentioned initial position. This operating cycle is repeated iteratively, by appropriate control of the aforementioned actuator.

In general, the cam profiles 7a and 21a combined make it possible to program in a precise and reproducible manner from one cycle to another, the position and the linear speed of the driven mobile 2 with respect to the position and the linear speed of the driving mobile 1. These cam profiles 7a are therefore determined specifically for each application, and more precisely as a function of the displacement (position and speed) desired for the driven mobile relative to displacement (position and speed) of the driving mobile .

In the particular application of Figures 1 to 7, and so 0666

not limiting of the invention, the cam profile 7a of the guide 7 successively comprises, from the aforementioned initial position of the driving mobile, a first horizontal rectilinear portion I, a first ascending portion II, a short substantially horizontal portion III, a descending portion IV and a horizontal rectilinear portion V. More particularly, in the example illustrated, the two ascending portions II and descending IV are symmetrical to one another and have the same slope. More particularly, the angle β formed by these two portions, relative to the direction the linear part I is identical to the angle α, and is more particularly 45 °. The movement in the “go” direction (arrow D) of the mobile assembly leading 1 / mobile driven 2 on this portion (I to V) of the guide 7 will now be detailed, it being specified that the skilled person is in able to immediately adapt the explanations given to understand the movement in the “going” direction (arrow D) of the moving assembly leading 1 / moving led 2 on the remaining part of the guide 7 (beyond the aforementioned portion V) , as well as the movement in the "return" direction (arrow D ') of the mobile assembly driving 1 / mobile driven 2.

At the start of the cycle, the rod 4 is supported by the crank pin 4b, on the above-mentioned rectilinear part I of the cam profile 7a, the rod 4a of the rod 4 being slightly inclined downwards as illustrated in the Figure 1 (initial angular position of the rod 4). It is considered in the following explanations that the part 10 of the driving mobile 1 is moved by the actuator in the direction D at a linear speed (V1), which may or may not be constant depending on the application.

In a first phase of the cycle, the part 20 of the driven mobile 2 is pushed by the link 4 whose crank pin 4b pushes on the cam profile 21 a of the part 20. The two parts 10 and 20 move linearly in the same direction D and with the same linear speed (V1), the difference between the two parts remaining constant, and the ,

rod 4 remaining in its abovementioned initial angular position. This movement of the two parts 10 and 20 at the same speed continues until the rod 4 comes into contact with the ascending portion II of the cam profile 7a (position illustrated in Figure 2). From the position illustrated in FIG. 2, the link 4 gradually pivots upwards (FIG. 3 / arrow F) under the action of guiding the portion II of the cam profile 7a. During this second operating phase, the crank pin 4b of the link 4 slides inside the light 21 and the driving mobile 20 is stopped (due to the same orientation of the light 21 and of the portion ascending II). The part 10 of the driving mobile 1 thus approaches part 20 of the driven mobile 2 which is stopped. The pivoting upwards of the rod 4 results in a compression of the spring mounted inside the tubular body 6a of the compression-expansion unit 6, which makes it possible to store energy which will be advantageously used to help on the subsequent restart of the driven mobile 2. This second operating phase continues until the link 4 arrives at the upper end of the ascending portion II of the cam profile 7a (position illustrated in FIG. 4).

In a third operating phase (not shown in the drawings), the link 4 is guided in contact with the rectilinear portion III, which results in a restart of the part 20.

In a fourth operating phase (FIGS. 5 and 6) the link 4 is guided in contact with the descending portion IV of the cam profile 7a. In this fourth operating phase, the part 20 of the driven mobile 2 is pushed by the link 4, said link pivoting downwards (FIG. 5 and 6 / arrow F '), and the crank pin 4b of the link 4 sliding in direction reverse in the light 21 of the part 20; the linear speed (V2) of movement of said part 20 is thus greater than the linear speed (V1) of part 10, part 20 03 00666

moving away from the part 10. During this downward pivoting of the link 4, the spring of the compression-relaxation unit 6, which was previously compressed, relaxes and restores the energy previously acquired, which facilitates restarting and acceleration of the moving part 20 during this fourth phase of operation.

When the connecting rod 4 comes into contact with the straight portion V of the cam profile 7a, the two ascending portions II and descending IV being perfectly symmetrical to each other, the difference between the two moving parts 10 and 20 has again become identical to the initial deviation of the aforementioned first operating phase, and the link 4 returns to its initial angular position in FIG. 1.

In a fifth operating phase, which corresponds to guiding the rod 4 by the rectilinear portion V of the cam profile 5, the two moving parts 10 and 20 move linearly at the same speed in the same way as for the first phase above operation, etc.

It will be understood in the light of the above explanations that the choice of the cam profile 7a and of the cam profile 21 of the light 21 conditions the different operating phases during a cycle, and in particular the relative position and relative speed of displacement of the driven mobile 2 relative to the driving mobile 1. These profiles will therefore be chosen by a person skilled in the art, depending on the application, and in particular the desired movement for the two mobile. The invention advantageously makes it possible, in a simple manner, to carry out operating cycles which are perfectly reproducible, with a precise and reproducible movement (position and speed) of the driven mobile with respect to the movement (position and speed) of the driving mobile. More particularly, the stop positions of the driven mobile are advantageously maintained whatever the external conditions, and are perfectly reproducible from one cycle to another. 0666

10

There is shown in Figures 8 to 12, a second alternative embodiment of a movable assembly leading V I driven mobile 2 ', in which the two mobiles move linearly in the same direction (arrows D and D'). For the sake of simplification, the parts of this assembly which fulfill the same function as the parts of the assembly previously described for the first variant of Figures 1 to 7, have been numbered with the same references. In this second variant embodiment, the guide 7 is formed by a plate in which a groove is formed, the internal face of which forms the cam profile 7a, and in which the crank pin 4b of the connecting rod 4 is guided. FIGS. 8 to 12 illustrate the movement of the two parts 10 and 20 respectively of the moving parts leading 1 ′ and driven mobile 2 ′ during a “outward” journey (arrow D) of the cycle. Note that in this embodiment, the cam profile 7a comprises two rectilinear portions (A) and (C) oriented at right angles, and connected by a curved portion (B). The first rectilinear portion (A) extends parallel to the direction of movement of the two mobiles (guide 3). The second rectilinear portion (C) extends transversely to this direction of movement. In addition, the rectilinear opening 21 of the part 20 of the mobile 2 'extends substantially parallel to the second rectilinear portion (C).

With reference to FIG. 8, when the connecting rod 4 is guided in the first rectilinear portion (A) of the cam profile 7a, the two mobiles move in the direction D (or D 'according to the direction of movement of the mobile leading 1' ) with the same linear speed.

With reference to FIGS. 9 and 10, when the part 10 of the driving mobile 1 'is moved in the direction D, and when the connecting rod 4 is guided by the curved connection portion (B), the mobile part 20 of the driven mobile 2' slows down compared to the part 10 of the mobile leading 1 '; the rod 4 pivots (arrow F) and the crank pin 4b of the 03 00666

11

rod slides in the light 21.

With reference to FIG. 11, when the connecting rod 4 is guided in the rectilinear portion (C) of the cam profile 7a, the part 20 of the driven mobile 2 'is immobilized, the part 10 of the driving mobile 1' approaching the part 20 of the driven mobile.

With reference to FIG. 12, when the crank pin 4 is in abutment against the end of the lumen 21, the part 10 of the driving mobile 1 ′ continues its movement in the direction D until it comes into the final stop position (end of the "outward" path), the link 4 continuing to pivot.

In the two variant embodiments which have just been described with reference to FIGS. 1 to 12, the guide 7 forming the first cam profile 7a, which allows the guide of the rod 4 is fixed. In another alternative embodiment, not illustrated, this guide 7 could be mounted on a carriage allowing its adjustment in position, or even be mobile during the displacement of the two parts 10 and 20. Also, in these two variants of FIGS. 1 to 12, the link 4 is in sliding contact with the two cam profiles 7a and 21a; in another variant, it could be a rolling contact, the crank pin 4b being for example provided with rollers of rotary bearings or equivalent. In the alternative embodiments illustrated in the appended figures, the link 4 is pivotally mounted relative to the driving mobile. This characteristic, although preferred, is not however limiting of the invention. In another variant, the link 4 may more generally be mounted to pivot and / or slide relative to the driving mobile. Similarly, the rod 4 can more generally be mounted to pivot and / or slide relative to the driven mobile.

There is shown in Figures 13 to 18, a third alternative embodiment, in which the mobiles leading 1 "and driven 2" respectively comprise two parts 10 and 20 mobile in rotation 0666

12

according to the same axis of rotation R. In this third alternative embodiment, the elements which fulfill the same functions as the first variant previously described have been indicated with the same references. Figures 13 to 17 attached which illustrate the different operating phases of the assembly 1 "/ 2" are sufficiently self-explanatory and will therefore not be detailed.

There is shown in Figures 19 to 22, a fourth embodiment, in which the moving parts leading 1 '"and driven 2'" are movable in rotation along an axis of rotation R.

With reference to FIGS. 19 and 20, the mobile leading 1 ″ is moved in rotation in the direction of the arrow F. This mobile leading 1 ″ is for example a rotary lever actuated manually or a lever actuated by a jack or equivalent . During the relative displacement of the two mobiles leading 1 ″ and 2 ″ with respect to each other, the force which is applied to the driving mobile 1 ″ is transmitted directly to the driven mobile 2 ″. The cam profile 7a is substantially parallel to the movement of the driven mobile 2 '".

When the two mobiles 1 '"and 2'" arrive in the position illustrated in FIG. 21, the force applied to the mobile "causes an available force on the mobile 2", increased in the gear ratio (or displacement). The cam profiles 7a and 21 cause a gear ratio and, therefore, to within accuracy, a force ratio between the two mobiles. When the two moving parts 1 "and 2" reach the final position of FIG. 22, the two cam profiles 7a and 21a are parallel, the two moving parts are separated. The mobile 2 '"is stopped, locked in position. The mobile l" is free to move without effect on the mobile 2' ", as long as the link 4b traverses the area of the cam 7a where the latter remains parallel to profile 21 a.

There is shown in Figures 24 to 26, a fifth variant 03 00666

^• 13

for carrying out the invention. Compared with the aforementioned fourth alternative embodiment, the mobile assembly leading 1 ″ and driven 2 ″ has two additional functionalities which will now be described, and in particular allows the clamping or clamping of a part 23.

For the implementation of a first additional functionality, the guide 7 is in connection with a non-return device 22, which in the illustrated example is in the form of a pawl 22a coming to cooperate with a peripheral toothing 22b of the guide 7. This non-return device 22 authorizes the guide 7 to follow the movement of the mobile leading 1 ″ as long as the driven mobile 2 ″ does not encounter any obstacles. Referring to FIG. 24, when the driven mobile 2 '"comes into contact with a part 23 to be clamped or clamped, the guide 7 is then prevented from moving back by the non-return device and becomes fixed. According to a second additional functionality, the driven mobile 2 '"has a prestressed device 24. Referring to FIG. 25, when the clamping jaw (M) carried at the end of the driven mobile 2'" is in contact with the part 23, the continuation of the movement of the moving part leading 1 ″ allows the prestressed device to be armed 24. The cam profiles 7a and 21a allow locking all of the two moving parts 1 ″ and 1 ″ after the arming phase of the prestressed device 24 The prestressed device 24 is released by the reverse action on the mobile leading to the ", and the manual or automatic release (not shown) of the non-return device 22.

FIG. 27 shows a sixth alternative embodiment of the invention, in which the axes of rotation R and R 'of the driving mobile 1'"and of the moving mobile driven 2 '" respectively are not merged, but are offset . The present invention finds its application in any industrial embodiment where it is necessary to drive a mobile (driven mobile) by a driving mobile, according to a fixed cycle, with a variable speed of movement of the driven mobile relative to the driving mobile, during a cycle. Its application is notably found in the production, in industrial equipment, of manipulator arms, of indexed transfer systems with linear displacement (first and second variant mentioned above) or with rotary displacement (third variant).

The invention also finds its application to the production of clamping or clamping devices. Finally, it should be stressed that the reversible character of the moving mobile / driven mobile assemblies which have been described with reference to the appended figures. For the sake of simplification of the description, it has been considered each time that the first mobile (1, 1 ', 1 ", 1" ") constitutes the driving mobile, and the second mobile (2, 2', 2", 2 '"), constituted the driven mobile. Of course, the operation of each assembly could be reversed, the second mobile (2, 2 ', 2 ", ...) being able to constitute a driving mobile, and the first mobile (1, 1', 1", ... ) constituting in this case the driven mobile.

Claims

Assembly comprising a first mobile (1; 1 '; 1 ";1'") and a second mobile (2; 2 '; 2 ";2'") and transmission means allowing a transmission of movement between the two mobile according to a fixed cycle during which the speed ratio between the two mobiles is not constant, one of the mobiles being a driving mobile, the other mobile being a driven mobile, characterized in that said transmission means comprise a guide (7) distinct from the two mobiles and defining a first cam profile (7a), and a rigid link (4) which connects the. first mobile (1; 1 '; 1 ";1'") to the second mobile (2; 2 '; 2 ";2'") so that the distance between the two driving and driven mobiles is variable, in that the second mobile (2; 2 '; 2 ";2'") has a guide portion (21) which forms a second cam profile (21 a), in that said connection (4) on the one hand is maintained resting on the first cam profile (7a) so that during movement of the first mobile (1; 1 ', ";1'") the rigid link (4) is moved while being guided permanently by the first cam profile (7a), and on the other hand cooperates with the second cam profile (21a) of the second mobile (2; 2 '; 2 ";2'") for the transmission of movement between the two mobile, the two cam profiles (7a, 21a) being chosen so that the speed ratio between the two mobiles during a cycle is not constant. Assembly according to claim 1 characterized in that the rigid connection (4) comprises a link which is pivotally / or slidingly mounted relative to the second mobile (2; 2 '; 2 ";2'"). Assembly according to claim 1 or 2 characterized in that the rigid link (4) comprises a link which is pivotally and / or sliding relative to the first mobile (1; 1 '; 1 ";1'"). Assembly according to one of claims 1 to 3 characterized in that the second mobile (2; 2 '; 2 ";2'") has a slot or groove (21) whose internal face (21 a) defines the second profile cam. Assembly according to one of Claims 1 to 4, characterized in that it further comprises a compression-expansion unit (6) which connects the first mobile (1; 1 ") and the connection (4), said a compression unit- trigger (6) being provided to be compressed when the first mobile (1; 1 ") approaches the second mobile (2; 2"), and to relax during the acceleration phases of the second mobile (2; 2 ") relative to the first mobile (1; 1 "). Assembly according to one of claims 1 to 5 characterized in that at least a portion (II; C) of the first cam profile (7a) is oriented in the same direction that the second cam profile (21 a) so that the second mobile (2; 2 '; 2 ";2'") is immobilized when the link (4) is guided by said portion

(Il; 0. Assembly according to one of claims 1 to 6 characterized in that the two mobiles are designed to move in translation in the same direction. Assembly according to one of claims 1 to 6 characterized in that the two mobile leading are mobile in rotation along the same axis (R) Assembly according to any one of claims 1 to 8 characterized in that it allows to fulfill a clamping or clamping function.