Linear drive eddy current brake

Abstract

A linear eddy current brake (WBS) consists of at least one brake pad (14) and at least one moving rotor with a magnet, the magnetic surface (12) of which generates electromagnetic induction within the brake pad (14) and induces eddy currents (23) around the magnetic surface. The invention is characterized in that the brake pad (14) is separated by a slot (19) in the brake pad into open sections (20) which are insulated from one another and which reduce the braking force of the eddy current brake (WBS). The open section (10) is electrically connected or short-circuited as required in order to increase the braking force of the WBS. Thus, the eddy currents (23) of the segmented brake pads (14) (S-brake pads) flow only in the respective opening segments (20) and in conductor regions (9) connecting the opening segments (20) on one side. The basic feature of the device for carrying out the method is thus that the S-brake pad (14) is functionally divided into a fastening region (11), a contact region (24), an electromagnetic induction region (10) and a conductor region (9), the region of the S-brake pad (14) except for the conductor region (9) being divided into a plurality of segments (20) which can be short-circuited as required by transversely extending grooves (19).

Description

Technical Field

[0001] Eddy current brakes (WBS) for linear drives are used for linear drives in the cabins of roller coasters or so-called free fall towers. As described in utility model DE 29506374 U1, WBS brake the vehicle in an unsafe manner at the end of the ride.

[0002] The WBS eddy current brake consists of a short, axially movable rotor and a fixed, solid brake pad mounted between magnets.

[0003] Blocky brake pads make it difficult to accelerate the car at the start of a new train journey. Therefore, the brake pads are extended from the space between the magnets. The mechanical equipment to extend the blocky brake pads is complex and expensive. This paper proposes a new method that allows the braking force of the WSB to be changed without retracting or extending the brake pads. Background Art

[0004] Figure 1 A front view of a linear drive eddy current brake according to the prior art is shown.

[0005] The eddy current brake WBS consists of a brake pad 1, a U-shaped slide 2 with two magnetic strips 3, magnets 4, an electromagnetic induction space 5 between the magnets and an inclined mounting profile 6 that fixes the brake pad 1 on a fixed platform 7. The slide 2 moves along a movement axis (linear axis). The three dimensions of the brake pad 1 are defined relative to the linear axis (movement axis) of the slide as follows:

[0006] The length of the brake pad 1 is aligned axially (along the linear axis, linearly, i.e., perpendicular to the plane of the drawing here), the height of the brake pad 1 is aligned transversely (transversely, i.e., in the plane of the drawing from bottom to top), and the width (thickness) of the brake pad 1 is aligned transversely (transversely, i.e., horizontally from left to right in the plane of the drawing).

[0007] The magnet is composed of the magnet width b m , magnet height h m and the electromagnetic induction of the magnet B m Definition. The magnetic area is equal to the product b m* h m The magnets are magnetized alternately along the magnetic strip 3, i.e. Figure 1 The relative magnets 4 are equally polarized, and the electromagnetic inductions of the relative magnets 4 are added in the electromagnetic induction space.

[0008] Brake pads are usually composed of a copper alloy and are approximately 6 mm thick, approximately 40 cm high and approximately 60 cm long. State-of-the-art brake pads 1 have a solid design.

[0009] Figure 2The side view of the solid brake pad 1 is shown, wherein three magnetic surfaces 12 and three eddy currents 13 are shown. The brake pad 1 is functionally divided into an electromagnetic induction region 10, a conductor region 9 and a profile region 11.

[0010] The shaded area 13 corresponds to the electromagnetic induction B of the magnet. m Submerged magnetic surface. The moving magnet induces annular eddy currents 13 which surround the magnetic surface 12 and slow down the slider.

[0011] The annular eddy current 13 is excited in the electromagnetic induction region 10 and is short-circuited by the conductor region 9 and the profile region 11. Equation (1) applies to the braking force F ws and solid brake pads I ws A first approximation of the eddy current: F ws ~I ws ~B m* b m 2 * h m (1)

[0012] Braking force F of solid brake pad 1 ws and eddy current I ws With magnetic electromagnetic induction B m , width b m 2 The square of the magnet height h m Proportional.

[0013] The existing technical solution uses the braking force to induce the magnetic electromagnetic induction B m - See the dependence of formula (1).

[0014] According to the method of patent specification EP 3451516 A1, it is proposed to move the magnetic strip of the slide axially by the magnet width b. m .

[0015] The induction of the magnets facing each other in the electromagnetic induction space is no longer equal, but opposite after the magnetic bar moves. The induction of the magnets in the electromagnetic induction space cancels each other out, and the braking force is reduced. If the magnetic bar moves back by the magnet width bm, the electromagnetic induction B in the electromagnetic induction space m Increases, and the braking force of the eddy current brake WBS increases.

[0016] In patent US 4,482,034, it is proposed to rotate part of the magnetic poles and thus adjust their braking effect. In DE 1053687 of the German Patent Office, a linear displacement of the magnet is proposed, similar to patent specification EP 3451516 A1. In CN105591523A, the rotating magnetic disk is decelerated by superimposing the magnetic field of the magnetic poles with the magnetic field of the current-carrying coil. By changing the direction of the current in the coil, the magnetic flux increases, decreases or turns off the braking effect of the magnetic poles. In another method, the braking force is changed by retracting or extending the brake pad from the induction cavity. If the solid brake pad is outside the electromagnetic induction cavity, there is no braking force. The further the brake pad is immersed in the electromagnetic induction cavity, the greater the braking force of the solid brake pad.

[0017] The accumulator and valve are configured in such a way that, in the event of a brake pad failure, the brake pad is retracted into the electromagnetic induction chamber, thereby providing full braking force in the event of a failure (fail-safe WBS). The energy required in the event of a failure is provided by the accumulator.

[0018] The following is a critical evaluation of the above prior art: Due to the strong attraction between the magnetic strips, the device to replace the magnetic strips (EP 3451516 A1, US 4,482,034) is complicated and costly. In addition, the device also requires the energy of the vehicle, which is not available in the cab of the roller coaster. Therefore, this method has not yet been established.

[0019] The use of current-carrying coils to control the braking effect of the magnetic poles is problematic because the coils are very large and the coil currents lead to losses and high temperatures. Furthermore, this method is only used for rotary eddy current brakes. The equipment for retracting and extending the brake pads consists of a pneumatically or hydraulically operated cylinder and a pressure accumulator. This equipment must be able to absorb the entire braking force and is therefore complex, bulky and expensive.

[0020] This criticism also applies to the pressure accumulator, which is the energy source required to immerse the brake pads in the electromagnetic induction chamber. Summary of the invention

[0021] In view of these disadvantages of the known designs, the task of the present invention is to create a method for controlling the braking force of a WSB which does not require expensive displacement of the brake pads.

[0022] Another task is to design the device in accordance with the apparatus required to implement the method. Another task is to achieve a ratio of at least nine to one between the maximum and minimum braking force of the controlled WSB. Another task is to design the device compactly so that an existing WSB can be replaced with the WSB controlled by the present invention.

[0023] These devices are intended to create short circuits between the segments of the S-brake pad, or to eliminate these short circuits.Another task of the invention is to define the characteristics and topology of the brake pad of the controlled WBS.

[0024] Braking force control devices should switch currents in the on / off range of several 1000 A, and the short-circuit resistance should be only a few milliohms. High losses and impermissibly high temperatures should be avoided.

[0025] If possible, the device should be able to handle up to 10 switching operations without failure. It must be fail-safe, i.e. maximum braking force must be generated in the event of a failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The solution to the technical problem comprises the method according to claims 1 to 3. The method can be implemented by the device according to claims 4 to 14. Therefore, according to the invention, the solid brake pad is divided into several segments. These segments are short-circuited to obtain a large braking force, or the short circuit is disconnected to reduce the braking force. The topology of the segmented brake pad and the device required to create and eliminate the short circuit between the segments of the brake pad are shown below.

[0027] The figure is used to illustrate the basic problem and shows the equipment to implement the method. These are described and explained below. show: Figure 1 : A front view of a linear drive eddy current brake according to the state of the art; Figure 2 : According to the situation in the field, a solid brake pad with three eddy currents is used; Figure 3 : Segmented brake pad with opening segment; Figure 4 : Brake pads with short-circuit short-road segmentation; Figure 5 : The structure of the switch; Figure 6 : Contact conductor with spring contact; Figure 7 : Contact conductor with plug contacts. DETAILED DESCRIPTION

[0028] The object of the present invention is achieved by dividing the area of ​​the conductive brake pad into several insulating segments. In the following, the segmented brake pad is called S-brake pad. The segmentation is achieved by installing grooves in the solid brake pad. The grooves insulate the conductive segments from each other, which are called open segments in the following.

[0029] Figure 3 The brake pad 14 is functionally divided into a profile area 11, an electromagnetic induction area 10 and a conductor area 9. The height of the electromagnetic induction area 10 is equal to or greater than the magnet height h m .

[0030] The contact area 17 of the S-brake pad 14 between the electromagnetic induction area 10 and the profile area 9 is divided into individual segments. Figure 3 In FIG. 1 , the contact areas 16 of the segments are shown together with the shaded areas 16. The two actuator areas 18 are used for the connection of the actuators.

[0031] The groove 19 preferably runs transversely through the electromagnetic induction region 10, through the contact region 17 and the profile region 11. Only the conductor region 9 is not segmented. The groove defines the mutually insulated segment widths b s Segment 20. The electromagnetic induction area 10 of the S-brake pad is covered by magnetic electromagnetic induction.

[0032] The contact area 17 of the S-brake pad 14 cannot short-circuit any eddy currents, since this area is interrupted by the grooves 19. The eddy currents 22 can only short-circuit within the segments 20. Therefore, the eddy currents 22 only surround the corresponding active segment surface 21, which is Figure 4 The braking force F of the S-brake pad 14 with the opening section 20 is shown in the shaded area. ws1 and eddy current I ws1 With segment width b s Proportional to the square of . The following applies: F ws1 ~I ws1 ~B m* b s 2 * h m (2)

[0033] The greater the number of opening segments 20 and the smaller the segment width, the smaller the eddy current and the braking force.

[0034] The width of the groove 19 of the S-brake pad 14 is in the millimeter range, and since the maximum voltage between two grooves is less than 50V, the groove 19 is preferably filled with an insulator to prevent impurities.

[0035] The size of the S-brake pad 14 is referred to as an equivalent brake pad. The braking force of the S-brake pad 14 having the opening section 20 can be reduced to less than 10% of the braking force of the equivalent brake pad.

[0036] If the conductor area 9 of the S-brake pad 14 is not affected by the leakage flux of the rotor magnets and is eddy current-free, the minimum braking force requirement is met. This requirement is achieved above the induction range of the magnets.

[0037] Figure 4 The shaded contact area 24 of the segmented brake pad 14 with the short-circuited segments 20 is shown. According to the present invention, the braking force of the S-brake pad 14 is greater when the segments 20 are short-circuited. The short-circuiting of the segments 20 occurs in the contact area 24.

[0038] like Figure 4As shown, the eddy current 23 of the S-brake pad 14 with the short-circuit section 20 surrounds the magnetic surface 12. Figure 2 As shown, the eddy current I of the S-brake pad 14 with the short-circuit section 20 ws2 Curve 23 and eddy current I of solid brake pad ws The curve of 13 is equivalent.

[0039] Equation (3) is equivalent to equation (1) and is applicable to the eddy current I of the S-brake pad 14 with the short-circuit section 20: ws2 and braking force F ws2 : F ws2 ~I ws2 ~B m* b m 2 * h m (3)

[0040] Therefore, the braking force of the S-brake pad 14 having the short-circuit section 20 can reach 90% of the braking force of the equivalent brake pad.

[0041] Apparatus suitable for applying the above method is described below.

[0042] The method according to claims 1 to 3, characterized in that Figure 4 As shown, the device for performing the method comprises two switches 30, which are mechanically connected to the two actuator areas 18 of the S-brake pad 14. Figure 5 As shown, the switch 30 includes two pairs of actuators 25 .

[0043] The pair of actuators 25 includes an ON actuator 26 and an OFF actuator 27, which move a contact conductor 28 having a spring contact 29. The OFF actuator 27 moves the contact conductor 28 with the spring contact to the OFF position, and the ON actuator 26 moves the contact conductor 28 with the spring contact to the ON position.

[0044] The segments 20 of the S-brake pad 14 are short-circuited by two contact conductors 28 with spring contacts 29. Two ON actuators 26 and two OFF actuators 27 are connected to the actuator region 18 of the S-brake pad 14, moving the two contact conductors 28 with the spring contacts 29, as shown in FIG. Figure 5 shown.

[0045] When the two ON actuators 26 of the S-brake pad 14 move the two contact conductors 28 to the ON position, the spring contacts 29 press on the two contact areas of the S-brake pad 14 and short-circuit the segments of the S-brake pad 14. This state is called the ON state. The segments 20 are short-circuited in this state, such as Figure 5 shown.

[0046] When the two OFF actuators 27 of the S-brake 14 move the two contact conductors 28 to the OFF position, the connection between the spring contact 29 and the segment 20 is disconnected. Therefore, the short circuit of the segment 20 is disconnected. This state is called the OFF state, and the segment 20 is in the OFF state. The ON switch and the OFF switch of the S-brake 14 are controlled at the same time.

[0047] like Figure 5 As shown, the housing 31 fixes the actuator pair 25 of the S-brake pad 14 on the fixing platform 7. The S-brake pad 16 is fastened to the fastening profile 6 by means of fastening screws 8. The fastening profile 6 fixes the S-brake pad 14 on the platform 8.

[0048] The fastening profile 6 and the fastening screw 8 are insulated from the S-brake pad 14. This prevents the fastening profile 6 from short-circuiting the segment 20 of the S-brake pad 14.

[0049] The structure of the contact conductor 28 is as follows Figure 6 As shown, the contact conductor 28 is connected to several individual spring contacts 29. The contact conductor 28 is provided with an actuator area 33 at each end thereof for mounting an actuator. The contact conductor 28 is made of a highly conductive metal (e.g., copper). The spring contacts 29 are made of a highly conductive spring alloy (e.g., bronze).

[0050] Figure 7 An embodiment of a contact conductor 32 with two rows of individual spring-type plug-in contacts 34 is shown, the contact conductor 32 having two actuator regions 33 for fastening the actuator. An S-brake is then clamped between the plug-in contacts 34.

[0051] The contact surface of each segment of the S-brake pad is divided into a conductive contact surface and an insulating contact surface when the S-brake pad is inserted into the contact point 34 for contacting the conductor. The insulating contact surface is covered with an insulating layer.

[0052] In the OFF state, the plug contacts 34 only contact the insulating contact surfaces; the segments remain insulated. In the ON state, the plug contacts 34 contact the conductive contact surfaces of the segments and short-circuit.

[0053] The two ON actuators move the plug contacts 34 to the conductive contact surfaces of the segments, and the OFF actuators move the plug contacts 34 to the insulating contact surfaces of the segments.

[0054] The contact surfaces of the spring contact 29, the plug contact 34 and the segment 16 are coated with contact material. The slot between the spring contact 29 and the plug contact 34 is filled with an insulator. The slot 19 of the S-brake pad is filled with an insulator to prevent conductive contamination. The ON actuator and the OFF actuator can be realized by electromechanical, pneumatic or hydraulic actuators, or actuated by pneumatic or hydraulic cylinders. The actuator is preferably a movable pneumatic or hydraulic cylinder.

[0055] The pressure collector and the valves operating the hydraulic or pneumatic ON actuator and OFF actuator are arranged in such a way that in the event of a fault, the sections of the S-brake pad are short-circuited.

[0056] The ON actuator of a fail-safe switch can be replaced or extended with one or more tension springs. In the event of a fault, the OFF actuator is deactivated and the tension springs automatically move the contact wires to the ON position.

[0057] The OFF actuator of the switch can be replaced or expanded with one or more compression springs, and the ON actuator remains unchanged.

[0058] S-The two contact conductors of the brake pad move synchronously to the ON position or the OFF position-Claim 13.

[0059] The position sensors provided report that the contact conductor has reached the ON position or the OFF position. The temperature sensor also registers and reports when the temperature of the spring or the contact of the insertable plug has reached a maximum value. This prevents the spring or the plug contact from welding to the segment. List of Numbers 1 brake pad 2 Slide device (Runner) 3 Magnetic strip 4 Magnets 5 Electromagnetic induction chamber 6 Fastening profile 7 Platform 8 Fastening screws 9-Stair Area 10 Electromagnetic induction range 11 Fastening area 12 Magnetic surface 13 Eddy Current 14S - contact surface of brake pad 15-16 section 20 17 Contact area 18. Control Scope The slot between 19 and 20 20 segments 21 Segment Surface 22. Eddy current in paragraph 20 23 Eddy currents around magnetic surfaces 24 Contact area 25 Brake pair 26 ON regulator 27 OFF regulator 28 Contact Manager 29 Spring contacts 30 Switch 31 Shell 32 contact conductors with two rows of separate spring-loaded plug contacts 1533 Control range 34 plug contacts

Claims

1. A method for controlling the braking force of a linear eddy current brake (WBS), characterized in that The linear eddy current brake (WBS) consists of at least one brake pad (14) and at least one moving rotor (2) having a magnet (4), the magnetic surface (12) of which generates electromagnetic induction in the brake pad (14) and induces eddy currents (13) around the magnetic surface, The grooves (19) in the brake pad (14) are used to divide and separate the brake pad (14) into open sections (20) that are insulated from each other, thereby reducing the braking force of the eddy current brake (WBS) compared to a continuous brake pad, and these open sections (20) are electrically connected or short-circuited as needed to increase the braking force of the WBS.

2. The method according to claim 1, characterized in that The eddy currents (22) of the segmented brake pad (14), the so-called S-brake pad (14), flow only in the respective opening segment (20) and in the conductor area (9) which connects the opening segment (20) on one side.

3. The method according to claims 1 and 2, characterized in that The eddy currents (22) surround the magnetic surfaces (12) of the S-brake pads (14) only in those S-brake pads (14) that have short-circuit sections (20).

4. A device for carrying out the method according to any one of claims 1 to 3, characterized in that The device comprises, as a linear eddy current brake (WBS), at least one brake pad (14) and at least one moving rotor (2) having a magnet (4), the magnetic surface (12) of which generates electromagnetic induction in the brake pad (14) and induces eddy currents (13) around the magnetic surface, The S-brake pad (14) is functionally divided into a fastening area (11), a contact area (17), an electromagnetic induction area (10) and a conductor area (9). Except for the conductor area (9), the area of ​​the S-brake pad (14) is divided by a transversely extending groove (19) into a plurality of segments (20) that can be short-circuited as needed.

5. The device according to claim 4, characterized in that A switch (30) for short-circuiting the segment (20) is provided as required, each of the switches (30) having two pairs of actuators (25), one pair of the actuators (25) being arranged on the left side of the S-brake pad (14) and one pair of the actuators (25) being arranged on the right side of the S-brake pad (14), (25) being arranged on the left side or the right side of the S-brake pad (14), and each pair of actuators (25) comprising an ON actuator (26) and an OFF actuator (27), and each pair of actuators (25) A spring contact (29) can be used to move a contact conductor (28) to an ON position or an OFF position, wherein the spring contact (29) of the contact conductor (28) in the ON position can be moved to the OFF position, wherein the spring contact (29) of the contact conductor (28) in the ON position contacts the contact surface of the segment (20) and short-circuits the segment (20), and wherein the spring contact (29) of the contact conductor (28) in the OFF position is insulated from the contact surface of the segment (20) by an air gap and thus does not short-circuit the segment (20).

6. The device according to any one of claims 4 to 5, characterized in that There is a fastening profile (6) for the S-brake pad (14) and the fastening screw (8) is insulated from the S-brake pad (14).

7. The device according to any one of claims 5 to 6, characterized in that: The contact conductor (28) is made of a conductive material, the spring contact (29) electrically connected to the contact conductor (28) is made of a conductive spring alloy, and actuator regions (18) connected to the actuator are formed at both ends of the S-brake plate (14).

8. The device according to any one of claims 5 to 7, characterized in that: The contact conductor (32) comprises two rows of separate spring-loaded plug contacts (15) and two actuator areas (33), the S-brake (14) being inserted between the plug contacts (15) and the plug contacts (15) being in contact with the contact surfaces of the segments (20) of the S-brake (14), wherein the contact surfaces of the segments (20) are divided into conductive and insulating contact surfaces, and the plug contacts (15) in the ON position contact the conductive contact surfaces and short-circuit the segments (20) of the S-brake (14), while the plug contacts in the OFF position contact the insulating contact surfaces of the segments (20) and thus do not short-circuit the segments (20).

9. The device according to any one of claims 5 to 8, characterized in that: The contact surfaces of the spring contact (29), the plug contact (15) and the segment (20) are coated with a contact material, and the groove (19) is filled with an insulator.

10. The device according to any one of claims 5 to 9, characterized in that: Each ON actuator (26) and each OFF actuator (27) includes a pneumatically or hydraulically controlled cylinder for driving.

11. The device according to any one of claims 5 to 10, characterized in that: Each ON actuator (26) is designed with one or more springs for its movement.

12. The device according to any one of claims 5 to 11, characterized in that: Each OFF actuator (27) is designed with one or more springs for its movement.

13. The device according to any one of claims 5 to 12, characterized in that: The contact conductors (28) of the S-brake pad (14) can be synchronously transferred to an ON state or an OFF state, and all the segments (20) of the S-brake pad (14) can be synchronously short-circuited or disconnected.

14. The device according to any one of claims 5 to 13, characterized in that There is a position sensor, by means of which the reaching of the contact conductor (28) into the ON position and the OFF position can be registered, and there is a temperature sensor for detecting the temperature of the spring contact (29).

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