JP2016080175A - Motion transmitting device between motor supplying rotational movement and load moved in translation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and effective motion transmitting device not requiring any large area and capable of being assembled into a brake system, in particular.SOLUTION: This invention relates to a motion transmitting device applied between a rotary motor M supplying a rotational motion and a load R to be translated. The motion transmitting device comprises a transmittance sleeve 10 rotatable and translatable around a rotating axis X and having a first thread part SF1 and a second thread part SF2 with different threads at the outside; a nut 20 fixed against translation and rotation and engaged with the first thread part SF1; and a gear rim 30 having an inner thread, the gear rim 30 being engaged with the second thread part and having a rotating drive outer peripheral surface cooperating with the rotating drive mechanism 40 supported by a shaft 41 of the motor M at its outside.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motion transmission device between a motor that supplies rotational motion and a load that is translated.

  There are already many motion transmission devices that convert rotational motion into translational motion.

  The object of the present invention is to develop a motion transmission device that is simple and effective, takes up less space, and in particular can be integrated in a brake system.

  To this end, the present invention is directed to a motion transmission device between a motor that supplies rotational motion and a load that is translated. The device is a transmission sleeve mounted about a rotation axis, free to rotate about the axis and translationally free along the axis, coupled to a load and externally threaded first threaded portion and A transmission rim having a second threaded portion, a nut that meshes with the first threaded portion of the sleeve, which is fixed non-translatably and non-rotatably, and a gear rim having an internal thread, engaging the second threaded portion And a gear rim having a rotary drive outer peripheral surface that cooperates with a rotary drive mechanism supported by a shaft of a motor on the outside.

  The motion conversion device according to the invention, in particular with a small diameter, allows a very wide variety of applications with a constant transmission ratio or a variable transmission ratio in the direction of increasing or decreasing ratio and at the same time a very large reduction of the thread pitch, While allowing reversibility of movement, it is not possible with just one screw thread.

This motion transmission device is inexpensive to manufacture and its function is very reliable.
The transmission of force is distributed between the two screw parts. This makes it easier to incorporate this motion conversion device into multiple types of actuators or auxiliary devices, as it allows for more effective transmission and especially less space.

  One or more threads with a variable pitch makes it possible to adapt a variable force to one output for two constant inputs, which has optimized the system with respect to its output Makes it easy to adapt to the motor.

  According to another feature, the threaded portions are aligned on the outer surface of the sleeve, and the diameter of the thread crest of the portion that engages the thread of the nut is smaller than the diameter of the crest of the gear rim. The threaded portion can pass through the gear rim without its thread engaging with it within the thread of the gear rim.

This advantageous form, which has a smaller diameter compared to the prior art, makes it possible to better fit a generally very limited tolerance space for incorporating an actuator in a motor vehicle.
According to another feature, the first threaded portion and the second threaded portion intersect on the sleeve along the axis.

This aspect allows for effective integration, for example, in an electric servo brake system, for example, due to its small diameter and length relative to the threaded gear rim.
According to another feature, the sleeve is hollow.

  The hollow sleeve, on the other hand, makes it easy to incorporate this motion conversion device in a mechanism that requires the shaft, rod, fluid tube, electrical cable or transmission cable to penetrate the inside of the sleeve to couple with the load. To do.

  The invention is also directed to a brake system including an electric servo brake and a master cylinder, characterized in that it also includes a motion converter. The case is fixed to a partition plate that separates the vehicle engine compartment and the cab, and the conversion device is controlled by a hollow sleeve that is penetrated by a push rod that couples the brake pedal to the master cylinder, and a control unit of the brake system. The motor drives a threaded gear rim as a function of the brake demand corresponding to the displacement of the push rod operated by the brake pedal, the displacement of the push rod being coupled to the control circuit of the brake system Detected by the sensor.

In particular, the conversion device is a conversion device having a sleeve with crossed threads.
In short, the motion conversion device makes it possible to fit well to the force / stroke operating curve in order to operate the master cylinder. In addition, the hollow sleeve allows penetration of the push rod of the pedal, which is generally space-saving and facilitates control of the servo brake and direct operation of the master cylinder in the event of a servo brake failure.

  In the following, the invention will be described in detail by means of various transmission devices between a motor and a load, using the attached drawings.

FIG. 1 is a schematic view of a first embodiment of a transmission device according to the present invention. FIG. 2 is a schematic view of a second embodiment of the transmission device according to the invention. FIG. 3 is a cutaway perspective view of an embodiment of the motion transmission device corresponding to the schematic diagram of FIG. FIG. 4 is a partial sectional perspective view of the motion transmission device according to the second embodiment corresponding to the principle diagram of FIG. FIG. 4A is a detailed view of the portion of the nut of FIG. 4 specifically illustrating the structure of crossed threads. FIG. 4B shows the studs extracted from the detailed view of FIG. FIG. 5A is a detailed view of a portion of a variation of a nut similar to the partial cross-sectional detail view of FIG. 4 showing the structure of crossed threads. FIG. 5B is a detailed view of a plurality of studs extracted from FIG. 5A, showing two thread roots of the thread embodiment of the nut embodiment of FIG. 5A. FIG. 6 is a schematic cross-sectional view of an apparatus of a brake system including a motion conversion device between a brake pedal and a master cylinder.

As shown in FIG. 1, the present invention is directed to a motion transmission device 1 that receives a rotational motion R ₀ of a motor M and applies a translational motion T (in both directions) to a load R.
The transmission device 1 having the axis line xx includes a sleeve 10, a nut 20, and a threaded gear rim 30.

The sleeve 10 having the axis xx is mounted to freely rotate about the axis xx and to freely translate along the axis xx. Sleeve 10, translation of the sleeve 10 (T) is transmitting, so that the rotational movement R ₁ is not transmitted, is coupled to a load R via a coupling mechanism 2.

Sleeve 10, the outer, first provided with a threaded portion SF ₁ and a second threaded portion SF _2, which are coaxial with respect to both the axis xx.
The nut 20 is prevented from rotating and translating. The axis xx coaxial nut 20 is engaged with the thread 11 of the threaded portion SF ₁ of the sleeve 10 through its threads 21.

Axis xx and the gear rim 30 with coaxial screws are engaged with the thread 12 of the threaded portion SF ₂ via its threads 31.
The threaded gear rim 30 has an outer peripheral surface 32 to rotate in cooperation with the output mechanism 40, and the output mechanism 40 is supported by the shaft 41 of the motor M and rotates. The rotational motion transmission coupling between the mechanisms 32 and 40 is, for example, a meshing coupling, teeth are provided on the outer peripheral surface 32, and the output mechanism 40 is a pinion. The threaded gear rim 30 is rotatable about the axis xx but is prevented from translation.

As shown in the embodiment of FIG. 1, the thread portions SF ₁ , SF ₂ continue to one another along the axis xx.
Since the diameter of the thread portion SF ₂ is sufficiently larger than the diameter of the thread portion SF ₁ , the crest diameter DI ₂ of the thread 31 is larger than the diameter of the thread 11, so that the thread 31 does not engage with the thread 11. . The peak diameter according to the present description is the diameter of a geometric cylinder with a circular cross section passing through the top of the thread and / or the peak.

This relationship between the diameters of the portions SF ₁ , SF ₂ allows the sleeve 10 to move more freely in the threaded gear rim 30 without the risk of the thread 11 engaging the thread 31. The choice of how large the inner diameter of the thread 31 that cooperates with the thread 12 relative to the equivalent elements of the nut 20 and the thread portion SF ₁ is a function of the motion (range of motion) that is to be transmitted to the load R. Depending on the movement of the sleeve 10 along the threads 11 and 12.

  The “floating” sleeve 10 is compounded and rotated by two pairs of threads 21/11 and 31/12 and appears as a translational movement T, which prevents the sleeve 10 from rotating or a locking nut. Compared to the translational movement of the sleeve 10 when there is no 20, it is raised or reduced somewhat.

  If the threads 11, 12 are, for example, constant, the motion speed increase / decrease ratio will be constant. However, it is equally conceivable to have a variable pitch so as to change the combined pitch of the sleeve 10 for one thread and even for both threads.

  This modification of the sleeve 10 makes it possible to have a variable stroke applied to the load R for an optimized input force. That is, the torque applied to the gear rim 30 will be constant.

It should also be noted that the sleeve 10 is typically shown as a hollow sleeve, but need not be hollow and may be a solid part.
FIG. 2 shows a modification of the motion transmission device of FIG. Since this variant of the device 1a generally has the same elements, the same elements have the same reference with the subscript a. These various elements which are similar or identical will not all be described in detail again.

Motion transmission device 1a, the embodiment device 1 of FIG. 1, the threaded portion _SF 1a, and _{SF 2a,} their thread 11a, 12a cooperate with threads 21a, a combination of 31a are different.

As shown in FIG. 2, the motion transmission device 1a includes a sleeve 10a, a nut 20a, and a threaded gear rim 30a.
The sleeve 10a is free to rotate around the axis xx of the device 1a and is free to translate along the axis xx of the device 1a.

The sleeve 10a is coupled to a load R via a coupling mechanism 2a, the coupling mechanism 2a is the load from the sleeve, translation T is the rotation motion R ₁ is not transmitted transmission.
The sleeve 10a is two screw portions _SF 1a, comprises _{SF 2a,} threaded portion _SF 1a, _{SF 2a} rather than continues along the axis xx, overlap with intersection around the sleeve 10a.

Since the threads 11a, 12a are in opposite directions, the transmission will slow down.
When supplied to the load via a constant input supplied by the motor M, the threads 11a, 12a may follow a constant or variable stroke / force curve even if one or two threads 11a, 12a are at a constant pitch. A variable pitch may be used.

The sleeve 10a via the screw portion SF _1a, rotation and translation engages a nut 20a that is fixed, and translation is fixed and rotating mesh with the gear rim 30a with free screws.

The threaded gear rim 30a is rotationally driven by a motor M and its rotation mechanism 40, for example, a pinion 40, and the pinion 40 meshes with the teeth 32a of the threaded gear rim 30a.
The thread portion SF _1a has a thread 11a, and the thread 11a extends, for example, over the entire length of the sleeve 10a and has a predetermined pitch.

The thread portion SF _2a has a thread 12a, and the thread 12a intersects the thread 11a of the section SF _1a and has a predetermined pitch, for example, over the entire length of the sleeve 10a.
Since the sleeve 10a is rotatable within the gear rim 30a over substantially the entire length of the nut 20a, the axial length (along xx) of the gear rim 30a is reduced compared to the gear rim 30 of the first embodiment. Is possible.

Similarly, it should be noted that sleeve 10a is shown as hollow, which is advantageous for many applications, but sleeve 10a may be a solid part.
Not only the embodiment of the sleeve 10a but also the embodiments of the screw threads 11a and 12a and the screw threads 21a and 31a show no particular difficulty.

  The crossed threads 11a, 12a of the sleeve 10a can, for example, first cut one thread and then cross the already formed thread and scrape the material to form the other thread, such as Thus, two threads 11a, 12a having a constant pitch are bounded by a curved parallelepiped stud, and the four faces of the stud are two screws, two at a time, as will be described in detail below. It will be composed of geometric surfaces of mountains.

If one or two threads have a variable pitch, the stud will be considered a distorted parallelepiped.
FIG. 3 shows a sleeve 10 capable of rotating and translating, a nut 20 fixed in translation and rotation, and a gear rim 30 fixed in translation but driven in rotation. It is an axial half sectional view of an embodiment. This figure shows the thread portions SF ₁ , SF ₂ and the crest diameter of the thread 31 that is larger than the crest diameter of the thread 11, whereby the sleeve 10 is threaded 31 to the left along FIG. 3. You can “forward” inside.

The driving means for the teeth 32 of the gear rim 30 are not shown.
A nut 20 with fixed rotation and translation is shown, for example, with its fixed opening 13.

FIG. 4 shows an axial half sectional view of an embodiment of the motion converter 1a of FIG. This embodiment differs from the embodiment of FIG. 3 as already described with respect to FIG.
FIG. 4 shows crossed threads 11a, 12a formed on the outer surface of the sleeve 10a. The crossed threads 11a, 12a constitute a stud 100a in the form of a parallelepiped having a curved surface. 100a forms two threads 11a, 12a, the discontinuities of which appear as thread roots.

Each thread 11a or 12a represents a number of parallel threads.
FIG. 4A is a partial view of FIG. 4 and FIG. 4B shows one stud of FIG. 4A, representing a particular shape of this stud 100a as a representative example of a stud.

  The valley bottom of the thread 11a is shown schematically by a spiral or quasi-helical band (constant or variable pitch), the direction of the band being indicated by a double arrow F11a. The spiral on the other side (rear side) of the stud 100a following the thread 11a is the same.

Thus, the screw thread 11a is formed by the two bottom surfaces 111a and 111aa by the valley bottom or track | orbit, and in the height of the stud 100a.
Similarly, thread 12a is shown schematically by track 12a. Similarly, the discontinuous thread 12a is bounded by the opposing surfaces 112a and 112aa at the height of the stud 100a.

  As a supplementary explanation, when the threads 11a, 12a have a variable pitch, the threads 21a, 31a are divided, for example, the threads 21a, 31a are formed on one or more variable pitch surfaces 111a, 111aa, 112a, 112aa. In order to absorb various curved surfaces, it is limited to a semi-vortex and has enough length to overlap several studs 100a at once and have sufficient guide and support contacts as a function of transmission force. I will.

  FIG. 5A shows crossed threads 11b, 12b, not shown in detail, on the outer surface of a sleeve 10b similar to the sleeve 10a of FIG. In this example, the threads 11b, 12b are shown as several parallel threads.

In the description of this modification, in order to show similar elements to FIGS. 4, 4A and 4B, the same reference numerals are used with the subscript b instead of the subscript a.
This variation of the intersecting threads 11b, 12b can be seen in the embodiment of FIGS. 4, 4A, 4B because the depth of the threads 11b differs from the depth of the threads 12b, as can be seen from the detailed view of FIG. 5B. Is different.

  Here again, the threads 11b, 12b are bounded by studs 100b formed by cutting the intersecting threads 11b, 12b. In the case of the special example of FIG. 5A, as can be seen from the right side of the sleeve 10b of FIG. To do.

  The opposing surfaces 111b and 111bb form a thread 11b, and the valley bottom 211b of the thread 11b is bordered by opposing side surfaces 311b and 311bb that join the surfaces 111b and 111bb. The surface 111b and the side surface 311b are present on the right-facing side visible in FIGS. 5A and 5B, while the surface 111bb and the side surface 311bb are present on the opposite surface hidden in the row of studs 100b.

  The opposing surfaces 112b and 112bb have a height up to the surfaces 311b and 311bb, and the valley bottom 212b of the thread 12b is discontinuous, interrupted by the thread 11b having a diameter smaller than the diameter of the thread 12b. The outer surface of the stud 100b is on the same cylindrical envelope surface. The threads 31 and 21 of the nut 20 and the threaded gear rim 30 have different peak diameters, and the peak diameter of the thread 21 that meshes with the thread 11b is smaller than the inner diameter of the thread 31 that meshes with the thread 12b shallower than the nut. It has an inner diameter (FIG. 5B). In this variant, the thread 21 is guided by a continuous part of the thread 11b bordered by the rings 311b, 311bb, while the thread 31 overlaps at least two studs 100b so that the movement is not disturbed. I will.

FIG. 6 schematically shows a servo brake with a motion converter according to the invention, which in this example is the converter 1a of FIGS. 2 and 4.
The brake system as shown is limited to a master cylinder, for example, a master cylinder tandem 200, which is coupled to a brake pedal 210 via a push rod 211. The push rod 211 cooperates with a sensor 220 to detect and control a brake request. The control unit 230 controls a motor (not shown) of the servo brake (for example, the motor M).

  The push rod 211 acts on the piston, for example, the primary piston of the master cylinder 200 indirectly through the servo brake and directly when the servo brake fails. The connection between the push rod 211 and the master cylinder 200 is only shown schematically, not various means known per se.

  With respect to the illustrated portion, the servo brake is composed of a motion conversion device 1a mounted behind a partition plate 240 that separates the vehicle engine compartment EM and the cab H. The conversion device 1a includes a case 250. The case 250 is fixed to the partition plate 240 by means not shown, and the case 250 is a component of the conversion device 1a, that is, the nut 20a integrated with the case 250, the servo brake. A sleeve 10a having a threaded gear rim 30a driven by a motor and two external thread threads 11a, 12a crossed is housed.

  The brake pedal 210 is pivotally connected about an axis 212, and the sleeve 10a projects into the cab H behind the pedal 210. However, this state is only a stationary position. When the pedal 210 is operated, the servo brake function appears as a movement of the sleeve 10a in the right direction shown in FIG. 5, where there are no protruding parts or components that limit the amplitude of the pivoting movement of the pedal.

This movement is preferably transmitted to the piston of the master cylinder 200 via the coupling 2a shown schematically, which transmits only the translation / thrust and not the rotation of the sleeve 10a.
The return movement of the sleeve 10a is controlled by a gear rim 30a driven in the reverse direction by a servo brake motor. The return movement of one or more pistons of the master cylinder is ensured by a restoring spring of the master cylinder.

  Besides this example of a servo brake system, the motion conversion device according to the invention is applicable to numerous mechanisms and actuators, especially in automotive technology.

DESCRIPTION OF SYMBOLS 1 Motion transmission apparatus 10 Sleeve 11 Thread part SF ₁ Thread 12 Screw part SF ₂ Thread 13 Fixed opening 20 Nut 21 Thread 30 Threaded gear rim 31 Thread 32 External surface / tooth surface 40 Rotating mechanism 41 Output shaft 100 Stud 111, 112 Stud surface 211b, 212b Valley bottom 311b, 311bb of thread 11b Side surface that borders thread 11b F11, F12 Thread direction M Motor R Load R ₀ Rotational speed of rotating mechanism 40 R ₁ Rotating speed of sleeve 10 SF ₁ First screw portion SF ₂ Second screw portion xx Axis of motion transmission device

  The present invention relates to a motion transmission device between a motor that supplies rotational motion and a load that is translated.

  There are already many motion transmission devices that convert rotational motion into translational motion.

  The object of the present invention is to develop a motion transmission device that is simple and effective, takes up less space, and in particular can be integrated in a brake system.

  To this end, the present invention is directed to a motion transmission device between a motor that supplies rotational motion and a load that is translated. The device is a transmission sleeve mounted about a rotation axis, free to rotate about the axis and translationally free along the axis, coupled to a load and externally threaded first threaded portion and A transmission rim having a second threaded portion, a nut that meshes with the first threaded portion of the sleeve, which is fixed non-translatably and non-rotatably, and a gear rim having an internal thread, engaging the second threaded portion And a gear rim having a rotary drive outer peripheral surface that cooperates with a rotary drive mechanism supported by a shaft of a motor on the outside.

  The motion conversion device according to the invention, in particular with a small diameter, allows a very wide variety of applications with a constant transmission ratio or a variable transmission ratio in the direction of increasing or decreasing ratio and at the same time a very large reduction of the thread pitch, While allowing reversibility of movement, it is not possible with just one screw thread.

This motion transmission device is inexpensive to manufacture and its function is very reliable.
The transmission of force is distributed between the two screw parts. This makes it easier to incorporate this motion conversion device into multiple types of actuators or auxiliary devices, as it allows for more effective transmission and especially less space.

One or more threads with a variable pitch allows the output to be variably adapted for a given input, which makes the system adaptable to a motor optimized for that output. make it easier.

  According to another feature, the threaded portions are aligned on the outer surface of the sleeve, and the diameter of the thread crest of the portion that engages the thread of the nut is smaller than the diameter of the crest of the gear rim. The threaded portion can pass through the gear rim without its thread engaging with it within the thread of the gear rim.

This advantageous form, which has a smaller diameter compared to the prior art, makes it possible to better fit a generally very limited tolerance space for incorporating an actuator in a motor vehicle.
According to another feature, the first threaded portion and the second threaded portion intersect on the sleeve along the axis.

This aspect allows for effective integration, for example, in an electric servo brake system, for example, due to its small diameter and length relative to the threaded gear rim.
According to another feature, the sleeve is hollow.

  The hollow sleeve, on the other hand, makes it easy to incorporate this motion conversion device in a mechanism that requires the shaft, rod, fluid tube, electrical cable or transmission cable to penetrate the inside of the sleeve to couple with the load. To do.

  The invention is also directed to a brake system including an electric servo brake and a master cylinder, characterized in that it also includes a motion converter. The case is fixed to a partition plate that separates the vehicle engine compartment and the cab, and the conversion device is controlled by a hollow sleeve that is penetrated by a push rod that couples the brake pedal to the master cylinder, and a control unit of the brake system. The motor drives a threaded gear rim as a function of the brake demand corresponding to the displacement of the push rod operated by the brake pedal, the displacement of the push rod being coupled to the control circuit of the brake system Detected by the sensor.

In particular, the conversion device is a conversion device having a sleeve with crossed threads.
In short, the motion conversion device makes it possible to fit well to the force / stroke operating curve in order to operate the master cylinder. In addition, the hollow sleeve allows penetration of the push rod of the pedal, which is generally space-saving and facilitates control of the servo brake and direct operation of the master cylinder in the event of a servo brake failure.

  In the following, the invention will be described in detail by means of various transmission devices between a motor and a load, using the attached drawings.

FIG. 1 is a schematic view of a first embodiment of a transmission device according to the present invention. FIG. 2 is a schematic view of a second embodiment of the transmission device according to the invention. FIG. 3 is a cutaway perspective view of an embodiment of the motion transmission device corresponding to the schematic diagram of FIG. FIG. 4 is a partial sectional perspective view of the motion transmission device according to the second embodiment corresponding to the principle diagram of FIG. FIG. 4A is a detailed view of the portion of the nut of FIG. 4 specifically illustrating the structure of crossed threads. FIG. 4B shows the studs extracted from the detailed view of FIG. FIG. 5A is a detailed view of a portion of a variation of a nut similar to the partial cross-sectional detail view of FIG. 4 showing the structure of crossed threads. FIG. 5B is a detailed view of a plurality of studs extracted from FIG. 5A, showing two thread roots of the thread embodiment of the nut embodiment of FIG. 5A. FIG. 6 is a schematic cross-sectional view of an apparatus of a brake system including a motion conversion device between a brake pedal and a master cylinder.

As shown in FIG. 1, the present invention is directed to a motion transmission device 1 that receives a rotational motion R ₀ of a motor M and applies a translational motion T (in both directions) to a load R.
The transmission device 1 having the axis line xx includes a sleeve 10, a nut 20, and a threaded gear rim 30.

The sleeve 10 having the axis xx is mounted to freely rotate about the axis xx and to freely translate along the axis xx. Sleeve 10, translation of the sleeve 10 (T) is transmitting, so that the rotational movement R ₁ is not transmitted, is coupled to a load R via a coupling mechanism 2.

Sleeve 10, the outer, first provided with a threaded portion SF ₁ and a second threaded portion SF _2, which are coaxial with respect to both the axis xx.
The nut 20 is prevented from rotating and translating. The axis xx coaxial nut 20 is engaged with the thread 11 of the threaded portion SF ₁ of the sleeve 10 through its threads 21.

Axis xx and the gear rim 30 with coaxial screws are engaged with the thread 12 of the threaded portion SF ₂ via its threads 31.
The threaded gear rim 30 has an outer peripheral surface 32 to rotate in cooperation with the output mechanism 40, and the output mechanism 40 is supported by the shaft 41 of the motor M and rotates. The rotational motion transmission coupling between the mechanisms 32 and 40 is, for example, a meshing coupling, teeth are provided on the outer peripheral surface 32, and the output mechanism 40 is a pinion. The threaded gear rim 30 is rotatable about the axis xx but is prevented from translation.

As shown in the embodiment of FIG. 1, the thread portions SF ₁ , SF ₂ continue to one another along the axis xx.
Since the diameter of the thread portion SF ₂ is sufficiently larger than the diameter of the thread portion SF ₁ , the crest diameter DI ₂ of the thread 31 is larger than the diameter of the thread 11, so that the thread 31 does not engage with the thread 11. . The peak diameter according to the present description is the diameter of a geometric cylinder with a circular cross section passing through the top of the thread and / or the peak.

This relationship between the diameters of the portions SF ₁ , SF ₂ allows the sleeve 10 to move more freely in the threaded gear rim 30 without the risk of the thread 11 engaging the thread 31. The choice of how large the inner diameter of the thread 31 that cooperates with the thread 12 relative to the equivalent elements of the nut 20 and the thread portion SF ₁ is a function of the motion (range of motion) that is to be transmitted to the load R. Depending on the movement of the sleeve 10 along the threads 11 and 12.

  The “floating” sleeve 10 is compounded and rotated by two pairs of threads 21/11 and 31/12 and appears as a translational movement T, which prevents the sleeve 10 from rotating or a locking nut. Compared to the translational movement of the sleeve 10 when there is no 20, it is raised or reduced somewhat.

If the threads 11, 12 are, for example, constant, the motion speed increase / decrease ratio will be constant. However, it is equally conceivable to have a variable pitch so as to change the pitch of the sleeve 10 for one thread and even for both threads.

  This modification of the sleeve 10 makes it possible to have a variable stroke applied to the load R for an optimized input force. That is, the torque applied to the gear rim 30 will be constant.

It should also be noted that the sleeve 10 is typically shown as a hollow sleeve, but need not be hollow and may be a solid part.
FIG. 2 shows a modification of the motion transmission device of FIG. Since this variant of the device 1a generally has the same elements, the same elements have the same reference with the subscript a. These various elements which are similar or identical will not all be described in detail again.

Motion transmission device 1a, the embodiment device 1 of FIG. 1, the threaded portion _SF 1a, and _{SF 2a,} their thread 11a, 12a cooperate with threads 21a, a combination of 31a are different.

As shown in FIG. 2, the motion transmission device 1a includes a sleeve 10a, a nut 20a, and a threaded gear rim 30a.
The sleeve 10a is free to rotate around the axis xx of the device 1a and is free to translate along the axis xx of the device 1a.

The sleeve 10a is coupled to a load R via a coupling mechanism 2a, the coupling mechanism 2a is the load from the sleeve, translation T is the rotation motion R ₁ is not transmitted transmission.
The sleeve 10a is two screw portions _SF 1a, comprises _{SF 2a,} threaded portion _SF 1a, _{SF 2a} rather than continues along the axis xx, overlap with intersection around the sleeve 10a.

Since the threads 11a, 12a are in opposite directions, the transmission will slow down.
When the translational movement T is supplied to the load R by a constant input supplied by the motor M, the threads 11a, 12a are pitched by one or two threads 11a, 12a according to a constant or variable stroke / force curve. Or a variable pitch.

The sleeve 10a via the screw portion SF _1a, rotation and translation engages a nut 20a that is fixed, and translation is fixed and rotating mesh with the gear rim 30a with free screws.

The threaded gear rim 30a is rotationally driven by a motor M and its rotation mechanism 40, for example, a pinion 40, and the pinion 40 meshes with the teeth 32a of the threaded gear rim 30a.
The thread portion SF _1a has a thread 11a, and the thread 11a extends, for example, over the entire length of the sleeve 10a and has a predetermined pitch.

The thread portion SF _2a has a thread 12a, and the thread 12a intersects the thread 11a of the section SF _1a and has a predetermined pitch, for example, over the entire length of the sleeve 10a.
Since the sleeve 10a is rotatable within the gear rim 30a over substantially the entire length of the nut 20a, the axial length (along xx) of the gear rim 30a is reduced compared to the gear rim 30 of the first embodiment. Is possible.

Similarly, it should be noted that sleeve 10a is shown as hollow, which is advantageous for many applications, but sleeve 10a may be a solid part.
Not only the embodiment of the sleeve 10a but also the embodiments of the screw threads 11a and 12a and the screw threads 21a and 31a show no particular difficulty.

  The crossed threads 11a, 12a of the sleeve 10a can, for example, first cut one thread and then cross the already formed thread and scrape the material to form the other thread, such as Thus, two threads 11a, 12a having a constant pitch are bounded by a curved parallelepiped stud, and the four faces of the stud are two screws, two at a time, as will be described in detail below. It will be composed of geometric surfaces of mountains.

If one or two threads have a variable pitch, the stud will be considered a distorted parallelepiped.
FIG. 3 shows a sleeve 10 capable of rotating and translating, a nut 20 fixed in translation and rotation, and a gear rim 30 fixed in translation but driven in rotation. It is an axial half sectional view of an embodiment. This figure shows the thread portions SF ₁ , SF ₂ and the crest diameter of the thread 31 that is larger than the crest diameter of the thread 11, whereby the sleeve 10 is threaded 31 to the left along FIG. 3. You can “forward” inside.

The driving means for the teeth 32 of the gear rim 30 are not shown.
A nut 20 with fixed rotation and translation is shown, for example, with its fixed opening 13.

FIG. 4 shows an axial half sectional view of an embodiment of the motion converter 1a of FIG. This embodiment differs from the embodiment of FIG. 3 as already described with respect to FIG.
FIG. 4 shows crossed threads 11a, 12a formed on the outer surface of the sleeve 10a. The crossed threads 11a, 12a constitute a stud 100a in the form of a parallelepiped having a curved surface. 100a forms two threads 11a, 12a, the discontinuities of which appear as thread roots.

Each thread 11a or 12a represents a number of parallel threads.
FIG. 4A is a partial view of FIG. 4 and FIG. 4B shows one stud of FIG. 4A, representing a particular shape of this stud 100a as a representative example of a stud.

  The valley bottom of the thread 11a is shown schematically by a spiral or quasi-helical band (constant or variable pitch), the direction of the band being indicated by a double arrow F11a. The spiral on the other side (rear side) of the stud 100a following the thread 11a is the same.

Thus, the screw thread 11a is formed by the two bottom surfaces 111a and 111aa by the valley bottom or track | orbit, and in the height of the stud 100a.
Similarly, thread 12a is schematically illustrated by track F 12a. Similarly, the discontinuous thread 12a is bounded by the opposing surfaces 112a and 112aa at the height of the stud 100a.

  As a supplementary explanation, when the threads 11a, 12a have a variable pitch, the threads 21a, 31a are divided, for example, the threads 21a, 31a are formed on one or more variable pitch surfaces 111a, 111aa, 112a, 112aa. In order to absorb various curved surfaces, it is limited to a semi-vortex and has enough length to overlap several studs 100a at once and have sufficient guide and support contacts as a function of transmission force. I will.

  FIG. 5A shows crossed threads 11b, 12b, not shown in detail, on the outer surface of a sleeve 10b similar to the sleeve 10a of FIG. In this example, the threads 11b, 12b are shown as several parallel threads.

In the description of this modification, in order to show similar elements to FIGS. 4, 4A and 4B, the same reference numerals are used with the subscript b instead of the subscript a.
This variation of the intersecting threads 11b, 12b can be seen in the embodiment of FIGS. 4, 4A, 4B because the depth of the threads 11b differs from the depth of the threads 12b, as can be seen from the detailed view of FIG. 5B. Is different.

  Here again, the threads 11b, 12b are bounded by studs 100b formed by cutting the intersecting threads 11b, 12b. In the case of the special example of FIG. 5A, as can be seen from the right side of the sleeve 10b of FIG. 5A, there are always four planes consisting of a parallel plane corresponding to the thread 11b and likewise a plane parallel to the thread 12b. To do.

  The opposing surfaces 111b and 111bb form a thread 11b, and the valley bottom 211b of the thread 11b is bordered by opposing side surfaces 311b and 311bb that join the surfaces 111b and 111bb. The surface 111b and the side surface 311b are present on the right-facing side visible in FIGS. 5A and 5B, while the surface 111bb and the side surface 311bb are present on the opposite surface hidden in the row of studs 100b.

The opposing surfaces 112b and 112bb have a height up to the surfaces 311b and 311bb, and the valley bottom 212b of the thread 12b is discontinuous, interrupted by the thread 11b having a diameter smaller than the diameter of the thread 12b. The outer surface of the stud 100b is on the same cylindrical envelope surface. The threads 31 and 21 of the nut 20 and the threaded gear rim 30 have different peak diameters, and the peak diameter of the thread 21 that meshes with the thread 11b is a thread that meshes with the thread 12b shallower than the thread 11b that meshes with the nut. It has an inner diameter smaller than 31 (FIG. 5B). In this variant, the thread 21 is guided by a continuous part of the thread 11b bordered by the rings 311b, 311bb, while the thread 31 overlaps at least two studs 100b so that the movement is not disturbed. I will.

FIG. 6 schematically shows a servo brake with a motion converter according to the invention, which in this example is the converter 1a of FIGS. 2 and 4.
The brake system as shown is limited to a master cylinder, for example, a master cylinder tandem 200, which is coupled to a brake pedal 210 via a push rod 211. The push rod 211 cooperates with a sensor 220 to detect and control a brake request. The control unit 230 controls a motor (not shown) of the servo brake (for example, the motor M).

The push rod 211 acts on the piston, for example, the primary piston of the master cylinder 200 indirectly through the servo brake and directly when the servo brake fails. The coupling between the push rod 211 and the master cylinder 200 is a variety of means known per se and is only shown in schematic form.

  With respect to the illustrated portion, the servo brake is composed of a motion conversion device 1a mounted behind a partition plate 240 that separates the vehicle engine compartment EM and the cab H. The conversion device 1a includes a case 250. The case 250 is fixed to the partition plate 240 by means not shown, and the case 250 is a component of the conversion device 1a, that is, the nut 20a integrated with the case 250, the servo brake. A sleeve 10a having a threaded gear rim 30a driven by a motor and two external thread threads 11a, 12a crossed is housed.

  The brake pedal 210 is pivotally connected about an axis 212, and the sleeve 10a projects into the cab H behind the pedal 210. However, this state is only a stationary position. When the pedal 210 is operated, the servo brake function appears as a movement of the sleeve 10a in the right direction shown in FIG. 5, where there are no protruding parts or components that limit the amplitude of the pivoting movement of the pedal.

This movement is preferably transmitted to the piston of the master cylinder 200 via the coupling 2a shown schematically, which transmits only the translation / thrust and not the rotation of the sleeve 10a.
The return movement of the sleeve 10a is controlled by a gear rim 30a driven in the reverse direction by a servo brake motor. The return movement of one or more pistons of the master cylinder is ensured by a restoring spring of the master cylinder.

  Besides this example of a servo brake system, the motion conversion device according to the invention is applicable to numerous mechanisms and actuators, especially in automotive technology.

DESCRIPTION OF SYMBOLS 1 Motion transmission apparatus 10 Sleeve 11 Thread part SF ₁ Thread 12 Screw part SF ₂ Thread 13 Fixed opening 20 Nut 21 Thread 30 Threaded gear rim 31 Thread 32 External surface / tooth surface 40 Rotating mechanism 41 Output shaft 100 Stud 111, 112 Stud surface 211b, 212b Valley bottom 311b, 311bb of thread 11b Side surface that borders thread 11b F11, F12 Thread direction M Motor R Load R ₀ Rotational speed of rotating mechanism 40 R ₁ Rotating speed of sleeve 10 SF ₁ First screw portion SF ₂ Second screw portion xx Axis of motion transmission device

Claims (6)

In a motion transmission device between a motor (M) for supplying rotational motion and a load (R) to be translated,
The device is mounted about an axis of rotation (X);
A transmission sleeve (10, 10a) which is free to rotate about an axis (xx) and is free to translate along an axis (xx), coupled to a load (R) and externally threaded first threaded portion The transmission sleeve (10, 10a) having (SF ₁ ) and a second threaded portion (SF ₂ );
A nut (20, 20a) that engages the first threaded portion (SF ₁ ) of the sleeve (10, 10a), fixed in a translational and non-rotatable manner;
A gear rim (30, 30a) having an inner thread (31, 31a), which is engaged with the second screw part (SF ₂ ) and supported on the outside by the shaft (41) of the motor (M). A rotary rim (30, 30a) having a rotary drive outer peripheral surface cooperating with the rotary drive mechanism (40), and a load (in translation) and a motor (M) for supplying rotational motion, R) motion transmission device. The threaded portions (SF ₁ , SF ₂ ) are arranged in a line on the outer surface of the sleeve (10),
The diameter of the crest of the thread (11) of the portion (SF ₁ ) that meshes with the thread (21) of the nut (20) is smaller than the diameter of the crest of the thread (31) of the gear rim (30). The threaded portion (SF ₁ ) of the sleeve (10) can pass through the gear rim (30) without engaging its thread (11) within the thread (31) of the gear rim (30). The transmission device according to claim 1, wherein the transmission device is provided. Transmission device according to claim 1 in which the first threaded portion _{(SF 1a)} and a second threaded portion _{(SF 2a)} characterized in that the intersecting on the sleeve (10a) along the axis (xx).   One of the crossed threads (11b, 12b) has a thread depth greater than that of the other crossed thread (12b), thereby allowing the stud (100b) to form a deep thread (11b). The faces (111b, 111bb) are complemented by an annulus (311b, 311bb) connecting the faces (111b or 111bb) to form a passage for guiding the thread (21) of the nut (20), The faces (112b, 112bb) are coupled via a spacing between the studs (100b) and the corresponding gear rim (30) thread (31) is higher than the nut (20) thread (21). The transmission device according to claim 3, wherein the transmission device has a thickness. In a brake system including an electric servo brake and a master cylinder,
The brake system includes the motion converter (1, 1a) according to any one of claims 1 to 4, and the case (250) of the motion converter (1, 1a) includes a vehicle engine compartment (EM) and a cab ( H) is fixed to the partition plate (240), and the conversion device (1, 1a) is a hollow sleeve (1) that is penetrated by a push rod (211) that couples the brake pedal (210) to the master cylinder (200). 10, 10a) and a motor (M) controlled by the control unit (230) of the brake system, the motor (M) being displaced by the push rod (211) operated by the brake pedal (210) Drive the threaded gear rim (30, 30a) as a function of the brake demand corresponding to the displacement of the push rod (211), the control circuit of the brake system Brake system including an electric servo-brakes and the master cylinder, characterized in that it is detected by the sensor (220) coupled to 230).   Brake system according to claim 5, characterized in that the conversion device is a conversion device (1a) having a sleeve (10a) with crossed threads (11a, 12a).

Images