MXPA00001621A - Integral throttle body and torque motor - Google Patents

Abstract

A throttle valve assembly having a direct current torque motor assembled and calibrated as a subassembly or unit and installed on the throttle body and the throttle plate subsequently installed. The rotor is a disc defining magnetic poles and an axial air gap with the stators which are assembled in a cup-shaped housing. The housing and stators are assembled over the rotor shaft and rotor and attached to a cover plate to form a motor subassembly. The shaft of the motor subassembly is inserted in bearings in the throttle body and the subassembly secured to the throttle body by fasteners through the cover plate. The throttle plate is then installed in a slot in the motor shaft through the air passage in the throttle body.

Description

INTEGRAL TORSION MOTOR AND TORQUE BODY BACKGROUND OF THE INVENTION The present invention relates to DC torsion motors of the type intended to rotate forward or reverse by less than a full revolution of the motor rotor. Torque motors of this type are typically used for servo-actuator devices, where the rotation in fraction of revolution of an arrow is required to perform a work function. In particular, torsion motors have found application for operating the air intake throttle valve of an internal combustion engine for vehicle applications, in response to a control signal provided by an electronic controller. This is due, in part, to the strict emission requirements of exhaust engines recently imposed for motor vehicles, which have required electronic control of the engine's operating parameters. In such internal combustion engine choke applications, and particularly motor choke applications for motor vehicles, it is desired to minimize the size and weight of the torque motor as it must be attached to the throttle body structure of the engine, and by both are subject to high temperature and vibration generated by the motor. In such engine throttling applications, the torsion motor must provide a substantial torque output with the minimum excitation current of the motor coil, because the motor is operating, in a typical automotive application, at relatively low voltages of the motor. order of 12-24 volts, direct current. Therefore, it has been desired to provide a throttle actuator for a vehicle engine operated by an electric motor to provide a torsion motor that produces a maximum torque with a minimum mass of the magnetic pole structure in the rotor and the stator for a coil excitation current given. It has also been particularly desired to provide a torsion motor for vehicle engine throttle applications that is robust and accurate in rotor placement in order to correctly position the vehicle throttle in response to an electric throttle control signal from an electric driver. on board. Furthermore, it has been desired to provide a torque motor of DC, low voltage, minimum mass and size, for a vehicle throttling application that does not require manufacture of magnetic flux coil or pole structure of relatively exotic materials or expensive high magnetic permeability, but which is capable of being manufactured from relatively inexpensive iron-based material. An example of a known throttle motor throttle arrangement is shown and described in U.S. Patent No. 4,698,535, issued to Shira i et al, which uses a disk-like rotor with permanent ring magnets, arranged axially in opposite manner. Said known throttle torsion engine is assembled on an arrow extending from a pre-assembled throttle valve body and has the disadvantage of being complex and difficult to assemble and calibrate. Known dc torques for vehicle engine throttle operation have provided the required torsion to ensure a proper throttle location for a given control signal; however, known torsion engine designs have proven prohibitive in production costs for high volume mass production vehicle applications, or have been prohibitively bulky and heavy, and have required difficult and complex assembly operations to install in the throttle valve of the vehicle engine and calibrate them when installed. So, it has long been desired to provide a DC torsion motor for servo-actuator operation at relatively low voltages, particularly for throttle positioning of the vehicle engine, having minimum mass and volume and maximizing the torque output of the same for an excitation current of the coil of the given motor, and that is easy to assemble, install and calibrate. SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact, low cost torsion motor capable of operation at relatively low voltages, and which provides maximum torsion output for a fraction of a revolution of rotation of the motor arrow in forward or reverse direction and has maximum energy density with respect to the mass and volume of the motor for a given level of electrical energization. It is an additional object of the present application to provide a particularly suitable torsion motor for use as a vehicle engine throttle actuator. The present invention provides a torsion motor having the magnetic flux coil including an axial free space of air formed between the coils of the stator and an annular rotor formed of ferrous material having pole segments permanently magnetized therein. Its magnetic components, particularly the stator and the rotor, are formed of low-cost ferrous material, such as carbon steel, with the stator disposed adjacent to a disk-shaped rotor having permanent magnets arranged around the periphery and forming a space axial free air with the stator. The stator, the stator coils, the rotor and the motor housing are preassembled on one end of the motor shaft and electrically calibrated as a unit or sub-assembly and then installed in a vehicle choke body with the the arrow on the bearing surfaces provided therein and the plate or the throttling member is subsequently assembled to the arrow. The pre-assembly of the motor to the arrow as a unit allows the motor to be electrically calibrated for rotational arrow movement before assembly in the vehicle's throttle body, thereby simplifying assembly, calibration and testing to a large extent, and in this way providing a relatively low cost torsion engine for vehicle choke applications. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross section taken through the median plane of a vehicle throttle valve assembly, employing the torsion motor of the present invention.; Figure 2 is an axonometric view of the valve assembly of Figure 1, with portions of the body removed; Figure 3 is an exploded view of the throttle valve and throttle valve assembly of the present invention, as viewed from the engine side; Figure 4 is an exploded view of the present invention, similar to Figure 3, taken on the opposite side of the throttling body; and Figure 5 is an axonometric view of the torque and arrow motor sub-assembly of the present invention.

Detailed Description of the Invention Referring to Figures 1 to 5, the throttle valve assembly of the present invention is generally indicated at 10 and includes a throttle body 12 having a torque motor unit or sub-assembly generally indicated at 14, assembled therein with the throttle arrow 16 extending transversely through the air inlet passage 18 formed in the throttle body. The arrow has a throttle valve member or throttle plate 20 attached thereto; as, for example, by insertion in a groove 22 formed in the arrow 16 and there secured by means of threaded fasteners 24. The arrow 16 is blocked on axially opposite sides of the throttle plate 20 by bearing surface means 26, 28 provided in the choke body. In presently preferred practice, the bearing surface means 28, adjacent to the motor unit 14, includes a ball guide. The engine unit or sub-assembly 14 includes a motor housing or bushing 30 that is attached to a cover 32 having formed, preferably integral with it, an electrical receptacle 34 which has electrical connector tips such as the tip 36 therein. provided with the housing 30 attached to the cover 32 by elastic closure of the slots 38 on tabs 40 disposed peripherally around the cover 32.

The arrow 16 has provided therein, in rotational moment attachment, a rotor 42 preferably formed of iron-based material and having at least two magnetic poles arranged in an opposite manner formed around it. The rotor member 42 can be formed with separately magnetized pole segment members 41, 43 attached to the rotor 42, as shown in Fig. 1. In the presently preferred practice of the invention, the rotor 42 is made of material a iron base in order to minimize material costs; however, it will be understood that other materials having a high magnetic permeability and capable of being magnetized can be used, if desired. A pair of stators 44, 46, each having a generally arcuate configuration, are nested within the housing and generally cup-shaped 30 and attached thereto. Each of the stators 44, 46 is formed of material having a high magnetic permeability, such as for example iron-based material, and has a coil denoted respectively by the reference numerals 48, 50, therein wound. The coils each have electrical terminals provided therein as denoted by reference numerals 52, 54, respectively. The stator members 44, 46 are secured to the housing 30 by any suitable device, such as welding or metal deformation; and each can be formed as a two-piece member, as shown in cross-section in Figure 1. It will be understood that the coil terminals 52, 54 are connected to the receptacle tips, such as tip 36, by connecting strips 56, 58 provided inside the cover 32, as shown in Figure 4. In the assembly, the stator members 44, 46 with the coils 48, 50 respectively wound therein, are installed in the housing 30.; and the rotor 42 and the arrow 16 are then arranged in the housing with the arrow 16 extending outwardly therefrom through the housing opening 60 and the housing 30 is attached to the cover 32, retaining the rotor therein. A spacer sleeve 62 is provided on the arrow 16 to position the rotor 42 axially with respect to the stators 44, 46, which spacer is shown in Figures 1 and 4. The sub-assembly 14 of the housing 30 of the rotor arrow and the cover 32 is then installed as a unit 14 in a bore 64 formed in a male 66 provided on the side of the throttle body 12 with the arrow 16 rotatably received in stubs 26, 28 in the choke body 12. The unit 14 is then secured to the male 66 by suitable fasteners such as screws 68 received through appropriate fitting nipples 70 provided in the cover 32 and threadedly engaging projections 72 correspondingly located. , formed in the male 66. The choke plate is then inserted into the slot 22 and secured by means of fasteners 24. In this way, the motor unit 14 can be pre-assembled and pre-calibrated for mechanical rotating positioning of the arrow 16 for electrical input signals given prior to assembly of the unit 14 in the throttle body, which greatly simplifies the manufacture of the throttle valve assembly and actuator 10. In this manner, the present invention provides an engine for single torque, low cost and simple to assemble and calibrate, for use as an engine throttle actuator, and is robust and compact or in size for its relatively high torsion output, which is a result of the relatively large mass of magnetic flux coil material. The motor unit is completed and calibrated as a unit and installed as a sub-assembly in a throttle valve body and the throttle plate installed to complete the throttle valve assembly. Although the invention has been described above with respect to the illustrated embodiments, it will be understood that the invention is capable of modifications and variations and is only limited by the following claims.

Claims (17)

1. CLAIMS 1. A motorized throttle valve assembly, comprising: (a) a throttle body defining an engine air inlet passage therethrough; (b) arrow means extending transversely through said inlet passage and muted for rotational movement in said body, said arrow means including their pulse portions extending externally of said body; (c) a valve member disposed in said entry passage and rotationally movable with said arrow means; (d) a rotor including material having a relatively high magnetic permeability, disposed in said arrow means in impulse arrangement with said arrow means, and including a plurality of pole segments magnetized therein; (e) a motor housing having a stator of relatively high magnetic permeability therein, said stator having a coil of conductive material wound therein and defining a pair of pole pole segments; (f) a mounting member having said motor housing attached thereto, said rotor retaining there with said arrow means received through said motor housing, said rotor pole segments defining, each, a free axial space of air with said stator pole segments; (g) means for attaching said mounting member to said body; and (h) connector terminal means connected to said coils and adapted for electrical connection thereto externally. The assembly defined in claim 1, wherein said motor housing member has a generally cup-shaped configuration; and said rotor has a generally disk-shaped configuration. The assembly defined in claim 1, wherein said throttle body includes a recess with said motor receiving member received in said recess and said mounting member serves as a closure for said recess. . The assembly defined in claim 1, wherein said rotor includes an annular member attached thereto and defining said magnetized pole segments. The assembly defined in claim 1, wherein said mounting member includes assembled electrical terminals in pin connection with terminals in said coils. The assembly defined in claim 1, wherein said rotor includes an annular member formed substantially of an alloy of iron (Fe), neodymium (Nd) and boron (B). The assembly defined in claim 1, wherein said motor housing has a generally cup-shaped configuration and said motor housing is closed by elastic adjustment in said mounting member. The assembly defined in claim 1, wherein said arrow means, said rotor, said housing and said mounting member are assembled as a sub-assembly and said sub-assembly is received in said body. The assembly defined in claim 1, wherein said arrow means is completely muted in said body. The method of making a throttle valve assembly of a motorized motor, comprising: (a) forming an air inlet passage in a throttle body; (b) arranging an arrow with a valve member therein transversely through said inlet passage and muffling the arrow for rotational movement in said body, and extending a portion of said arrow externally of said body; (c) arranging a rotor on the external portion of said arrow and providing a pair of magnetized poles on said rotor; (d) providing a stator having a pair of stator poles and arranging said rotor pole segments axially adjacent said stator poles and securing said housing to a cover member and forming a subset of said rotor, stator, housing and cover; and (e) joining said sub-set to said body. 11. The method defined in claim 10, wherein said step of disposing an arrow includes joining said sub-assembly to said housing and subsequently joining said valve member to said arrow. The method defined in claim 10, wherein said step of joining said sub-assembly includes forming a cavity in said body externally of said inlet passage, arranging said housing in said cavity and securing said cover member over said cavity. The method defined in claim 10, wherein said step of forming a rotor-stator sub-assembly includes providing electrical terminals in said coils and connecting said terminals to said cover by pin connection. The method defined in claim 10, wherein said step of providing magnetized poles in said rotor includes attaching a magnetized annular member to said rotor. The method defined in claim 10, wherein said step of muting said arrow comprises muting said arrow on opposite sides of said entry passage. The method defined in claim 10, wherein said step of muting said arrow comprises muting said arrow completely in said body and on opposite sides of said entry passage. The method defined in claim 10, wherein said step of providing a pair of magnetized poles comprises arranging a pair of permanent magnets in said rotor.