GB1595837A - Speed signal generators particularly for injection timers - Google Patents

Speed signal generators particularly for injection timers Download PDF

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Publication number
GB1595837A
GB1595837A GB2148178A GB2148178A GB1595837A GB 1595837 A GB1595837 A GB 1595837A GB 2148178 A GB2148178 A GB 2148178A GB 2148178 A GB2148178 A GB 2148178A GB 1595837 A GB1595837 A GB 1595837A
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United Kingdom
Prior art keywords
contact surface
rolling elements
signal generator
speed signal
interruptions
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2148178A
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of GB1595837A publication Critical patent/GB1595837A/en
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/02—Devices characterised by the use of mechanical means
    • G01P3/16—Devices characterised by the use of mechanical means by using centrifugal forces of solid masses

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • High-Pressure Fuel Injection Pump Control (AREA)

Description

(54) IMPROVEMENTS IN OR RELATING TO SPEED SIGNAL GENERATORS PARTICULARLY FOR INJECTION TIMERS (71) We, ROBERT BOSCH G.m.b.H., a German company, of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to speed signal generators, particularly for injection timers.
Speed signal generators are known in which rolling elements which are subjected to centrifugal force and which are guided in a guide and are radially displaceable, in dependence upon 'the drive speed against the action of at least one spring roll between a contact surface preferably a bell-shaped contact surface, rotated by a drive and a stationary contact surface, wherein the distance between the contact surfaces is variable in dependence upon rotational speed by radial displacement of the rolling elements.
In one known speed signal generator the rolling elements are in the form of balls and are guided in a guide cage provided with slots. Undesirable friction occurs at the points at which the balls are in contact with the guide cage, thus leading to inaccuracies of adjustment. Furthermore, balls have to be guided in the guide cage with a certain amount of play, thus impairing the smooth running and accurate adjustment of the balls in dependence upon centrifugal force.
In another such speed signal generator in the range of low rotational speed interruptions are provided in one of the contact surfaces on which the rolling elements roll, the interruptions being uniformly distributed around the periphery and the number of interruptions being twice that of the number of rolling elements. The interruptions in the contact surface are relatively small and cause impacts which are intended to reduce the friction of the governor in the low range of rotational speed.
In a further such speed signal generator spherical rolling elements are displaced in dependence upon speed by providing corresponding contact surfaces on pivotable levers which are displaced by centrifugal force against the action of springs in dependence upon rotational speed. The balls are held in holes in a guide cage. As a result of the friction in this guide cage and the pivotable arms, an adjusting flange cannot be accurately adjusted in dependence upon rotation speed.
According to the present invention there is provided a speed signal generator, in which rolling elements which are guided by a guide spider and which when in operation are subjected to centrifugal force and are radially displaceable in dependence upon the drive speed against the action of at least one spring, are adapted to roll between a contact surface rotated by a drive and a stationary contact surface, wherein the distance between the contact surfaces is variable in dependence upon rotational speed by radial displacement of the rolling elements, and in which the guide spider has guide pins which are radially directed in a star-like manner for the radial guidance of each individual rolling element.
By embodying the present invention the rolling elements can be accurately guided in a circumferential direction and, for the purpose of driving them, do not have to be guided by a guide acting upon the outer circumference. Thus, the indication errors caused by friction can be greatly reduced.
The possibility of oscillation of the rolling elements can be greatly limited by accurate guidance on the guide pins, thereby at the same time reducing wear on parts in contact with one another.
Each rolling element is preferably held in a radial direction by at least one spring opposing the centrifugal force. Thereby, the radial position can be accuately determined by the centrifugal force, and the effects of friction can be largely excluded. The free adjustment of each rolling element can be substantially promoted if interruptions, set back relative to the actual contact surface are distributed around one of the contact surfaces, extend, and are distributed, over the entire contact surface associated with the entire range of speed. Each rolling element when located in a region of interruption in the contact surface can adjust itself entirely freely and accurately with respect to position in conformity with the centrifugal force and the opposing spring force. The total of the residual contact surfaces is always greater than the total of the surface of the interruptions in the contact surface. This also applies to the circular rolling paths of each individual orbit of the rolling elements, the residual contact surfaces being circumferentially distributed such that at least some of the rolling elemens cooperate with both contact surfaces.
Particularly satisfactory smooth running can be obtained with a minimum of wear in if the transitions between the residual contact surfaces and the interruptions in the contact surface are uniform in a circumferential direction and have only a small amount of curvature.
Particularly satisfactory smooth running can be obtained with a minimum of wear in if the transitions between the residual contact surfaces and the interruptions in the contact surface are uniform in a circumferential direction and have only a small amount of curvature.
The contact surfaces can be produced in a particularly simple manner when the residual contact surfaces and the interruptions in the contact surface are of substantially circular-sector-like configuration, the circular sector angle of the residual contact surfaces being greater than the circular sector angle of the interruptions in the contact surface.
In order to exclude vibratory excitation as far as possible, the number of the rotating rolling elements can be chosen so that it is not a multiple of the residual contact surfaces and/or interruptions in the contact surface.
The same also applies when the speed signal generator is used as a timer in an injection pump having a plurality of pump elements, the number of rolling elements, residual contact surfaces and interruptions in the contact surface then being chosen such that they do not correspond to the number of, or to an integral multiple, or a proper fraction of the number of pump elements provided.
The rolling elements are reliably guided in a particularly advantageous manner by securing the guide pins to a ring which is guided so as to be rotatable and displaceable in an axial direction. The rolling elements themselves may be at least part spherical, although, for the purpose of saving weight, they can each be in the form of a disc-like roller ring and have a bearing bore for receiving the respective guide pin.
For the purpose of supporting the rolling elements against centrifugal force, at least one compression spring is provided in a simple manner between the outer end of the respective guide pin and the rolling element, and, for the purpose reducing friction and wear, is advantageously arranged between sliding washers. For the purpose of reducing friction, these sliding washers can be additionally provided with a surface which reduces friction.
The adjustable contact surface of the speed signal generator can be provided in a particularly simple manner on a rotating, axially displaceable adjusting flange having a bellshaped contact surface. By virtue of the alternating transition of the roller elements to the contact surface from the interruptions in the contact surface, and vice versa, small pulses are in each case imparted to the adjusting flange and enable the existing friction to be overcome substantially more readily.
In a preferred embodiment, a drive shaft of the drive is coupled to an injection pump shaft by means of the adjusting flange and, upon axial displacement of the adjusting flange, the two shafts are angularly adjustable relative to one another for the purpose of timing the injection. Advantageously, helical splines for relative rotation of the shafts upon axial displacement of the adjusting flange are arranged such that the adjusting flange is displaced towards the rolling elements by the drive torque. This effect can be further enhanced by means of an additional spring.
The invention will be further described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a section through an injection timer according to one embodiment of the invention; Fig. 2 is a detail end elevation, taken on the line Il-Il of Fig. 1, of the adjusting flange having residual contact surfaces and interruptions in the contact surface, and Fig. 3 is a development of the periphery of the adjusting flange illustrated in Fig. 2, taken on the circular line III shown by a dash-dot line in Fig. 2.
An injection pump shaft 3 and a drive shaft 4 are rotatably journalled in a flange 1 of an injection pump (not illustrated) and in a housing 2 bolted to the flange. The two shafts 3 and 4 are angularly adjustable relative to one another for the purpose of injection timing. For this purpose, ajournal 5 of the drive shaft 4 is rotatably received in a bore in the injection pump shaft 3, and axially parallel guide splines 6 are provided on the injection pump shaft 3, whilst helical splines 7 are provided on the drive shaft 4 and are engaged by corresponding countersplines of an adjusting flange 8 of a speed signal generator 10 which serves as an injection timer 9.
The side of the adjusting flange 8 facing the flange 1 is of bell-shaped construction and, at this location, the adjusting flange forms a contact surface 11 which rotates with the drive shaft 4, while the flange 1 provides a further, fixedly arranged contact surface 12, and four rolling elements 13 roll between the two said contact surfaces. The rolling elements 13 are each rotatable and displaceable in a radial direction on an individual guide pin 14 of a guide spider 15. For this purpose, the guide pins 14 are secured to the outside of a ring 16 so as to extend radially. The ring 16 itself is rotatably and axially displaceably guided on a hub 17 of the adjusting flange 8, so that the guide spider 15 is driven by the rolling elemens 13 to rotate at approximately half the speed of the drive shaft 4. The rolling elements 13 themselves are of disc-like construction and have a bearing bore 18 for the guide pins 14. A spring 21 is provided between sliding washers 19 and 20 for the purpose of compensating for the centrifugal force. Alternatively, however, a plurality of graduated springs can be provided in order to obtain a corresponding radial position of the rolling elements 13 in dependence upon the centrifugal force and in conformity with the rotational speed of the drive shaft 4.
The stationary contact surface 12 of the flange I is of planar construction, while the oppositely located contact surface 11 of the adjusting flange has deeper located interruptions 22 offset in an axial direction, so that the contact surface 11 comprises these inter- ruptions 22 and residual contact surfaces 23-F of circular-sector-like configuration. The circular sector angle 24 of the residual contact surfaces 23 is larger than the circular sector angle 25 of the contact surface interruptions 22. The transitions 26 between the residual contact surfaces 23 and the interruptions 22 in the contact surface are smooth, so that the rolling elements 13 rolling on the residual contact surfaces 23 run onto them and off them smoothly. Fig. 3 shows a development of the contact surface 11 along a path indicated by a dash-dot line III in Fig. 2, with the four rolling elements 13, chosen in the embodimentm shown in exemplary instantaneous positions.
The arrangement described above operates in the following manners.
Torque to be transmitted by the drive shaft 4 to the injection pump shaft 3 displaces the adjusting flange 8 towards the flange 1, so that the rolling elements 13, held frictionally between the contact surfaces 11 and 12, are rotated. The rotational speed of the guide spider 15 having th guide pins 14 is approximately half tIe rotational speed of the adjusting flange 8. The rolling elements 13 are each forced outwardly by the centrifugal force occurring and supported by the respective spring 21. In order to ensure that the rolling elements 13 each assume an accurate position dependent upon the respective spring 21 and the rotational speed, irrespective of any friction occurring, two of the rolling elements 13 in the region of the interruptions 22 in the contact surface are in each case freely displaceable on the respective guide pin 14 and assume the corresponding speed-dependent position which they substantially maintain whilst they are running between the residual contact surfaces.
The position of each of the rolling elements 13 can then be corrected again in the following interruption 22 by the spring 21 irrespective of frictional forces. Thus, adjustment of the rolling elements 13 is independent of load or power transmission.
In conformity with the position of the rolling elements 13 on the guide pins 14, the adjusting flange 8 is axially displaced in dependence upon the shape of the bellshaped contact surface 11. The axial displacement in turn effects mutual relative angular displacement of the shafts 3 and 4, and thus effects corresponding injection timing.
Preferably, the angle a of slope of the contact surface 11 is smaller than or no more than, the angle of friction effective on the rolling elements 13, so that unintentional radial displacement of the rolling elements 13 is avoided by the self-locking action caused by the frictional connection between the rolling elements 13 and the contact surface 11.
It will be appreciated that the axial displacement of the adjusting flange 8 of the speed signal generator 10 can also be used directly as a speed measurement for other purposes, such as for the purpose of governing the speed of an injection pump, or can be further evaluated by way of an electronic transducer.
WHAT WE CLAIM IS: 1. A speed signal generator, in which rolling elements which are guided by a guide spider and which when in operation are subjected to centrifugal force and are radially displaceable in dependence upon the drive speed against the action of at least one spring, are adapted to roll between a contact surface rotated by a drive and a stationary contact surface, wherein the distance between the contact~ surfaces is variable in dependence upon rotational speed by radial displacement of the rolling elements, and in which the guide spider has guide pins which are radially directed in a star-like manner for
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (18)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    on the injection pump shaft 3, whilst helical splines 7 are provided on the drive shaft 4 and are engaged by corresponding countersplines of an adjusting flange 8 of a speed signal generator 10 which serves as an injection timer 9.
    The side of the adjusting flange 8 facing the flange 1 is of bell-shaped construction and, at this location, the adjusting flange forms a contact surface 11 which rotates with the drive shaft 4, while the flange 1 provides a further, fixedly arranged contact surface 12, and four rolling elements 13 roll between the two said contact surfaces. The rolling elements 13 are each rotatable and displaceable in a radial direction on an individual guide pin 14 of a guide spider 15. For this purpose, the guide pins 14 are secured to the outside of a ring 16 so as to extend radially. The ring 16 itself is rotatably and axially displaceably guided on a hub 17 of the adjusting flange 8, so that the guide spider 15 is driven by the rolling elemens 13 to rotate at approximately half the speed of the drive shaft 4. The rolling elements 13 themselves are of disc-like construction and have a bearing bore 18 for the guide pins 14. A spring 21 is provided between sliding washers 19 and 20 for the purpose of compensating for the centrifugal force. Alternatively, however, a plurality of graduated springs can be provided in order to obtain a corresponding radial position of the rolling elements 13 in dependence upon the centrifugal force and in conformity with the rotational speed of the drive shaft 4.
    The stationary contact surface 12 of the flange I is of planar construction, while the oppositely located contact surface 11 of the adjusting flange has deeper located interruptions 22 offset in an axial direction, so that the contact surface 11 comprises these inter- ruptions 22 and residual contact surfaces 23-F of circular-sector-like configuration. The circular sector angle 24 of the residual contact surfaces 23 is larger than the circular sector angle 25 of the contact surface interruptions 22. The transitions 26 between the residual contact surfaces 23 and the interruptions 22 in the contact surface are smooth, so that the rolling elements 13 rolling on the residual contact surfaces 23 run onto them and off them smoothly. Fig. 3 shows a development of the contact surface 11 along a path indicated by a dash-dot line III in Fig. 2, with the four rolling elements 13, chosen in the embodimentm shown in exemplary instantaneous positions.
    The arrangement described above operates in the following manners.
    Torque to be transmitted by the drive shaft 4 to the injection pump shaft 3 displaces the adjusting flange 8 towards the flange 1, so that the rolling elements 13, held frictionally between the contact surfaces 11 and 12, are rotated. The rotational speed of the guide spider 15 having thé guide pins 14 is approximately half tIe rotational speed of the adjusting flange 8. The rolling elements 13 are each forced outwardly by the centrifugal force occurring and supported by the respective spring 21. In order to ensure that the rolling elements 13 each assume an accurate position dependent upon the respective spring 21 and the rotational speed, irrespective of any friction occurring, two of the rolling elements 13 in the region of the interruptions 22 in the contact surface are in each case freely displaceable on the respective guide pin 14 and assume the corresponding speed-dependent position which they substantially maintain whilst they are running between the residual contact surfaces.
    The position of each of the rolling elements
    13 can then be corrected again in the following interruption 22 by the spring 21 irrespective of frictional forces. Thus, adjustment of the rolling elements 13 is independent of load or power transmission.
    In conformity with the position of the rolling elements 13 on the guide pins 14, the adjusting flange 8 is axially displaced in dependence upon the shape of the bellshaped contact surface 11. The axial displacement in turn effects mutual relative angular displacement of the shafts 3 and 4, and thus effects corresponding injection timing.
    Preferably, the angle a of slope of the contact surface 11 is smaller than or no more than, the angle of friction effective on the rolling elements 13, so that unintentional radial displacement of the rolling elements
    13 is avoided by the self-locking action caused by the frictional connection between the rolling elements 13 and the contact surface 11.
    It will be appreciated that the axial displacement of the adjusting flange 8 of the speed signal generator 10 can also be used directly as a speed measurement for other purposes, such as for the purpose of governing the speed of an injection pump, or can be further evaluated by way of an electronic transducer.
    WHAT WE CLAIM IS: 1. A speed signal generator, in which rolling elements which are guided by a guide spider and which when in operation are subjected to centrifugal force and are radially displaceable in dependence upon the drive speed against the action of at least one spring, are adapted to roll between a contact surface rotated by a drive and a stationary contact surface, wherein the distance between the contact~ surfaces is variable in dependence upon rotational speed by radial displacement of the rolling elements, and in which the guide spider has guide pins which are radially directed in a star-like manner for
    the radial guidance of each individual rolling element.
  2. 2. A speed signal generator as claimed in claim 1, in which the rotatable contact surface is a bell-shaped surface.
  3. 3. A speed signal generator as claimed in claim 1 or 2, in which one of the contact surfaces has circumferentially distributed interruptions which are set back relative to the residual contact surface and are distributed over the entire contact surface and are effective over the entire range of speed.
  4. 4. A speed signal generator as claimed in claim 3, in which the total of the residual contact surface is greater than the total surface of the interruptions in the contact surface.
  5. 5. A speed signal generator as claimed in claim 3 or 4, in which the transitions between the residual contact surfaces and the interruptions in the contact surface are smooth.
  6. 6. A speed signal generator as claimed in any of claims 3 to 5, in which the residual contact surfaces and the interruptions in the contact surface are of substantially circularsector-like construction.
  7. 7. A speed signal generator as claimed in claim 6, in which the circular sector angles of the residual surfaces are larger than the circular sector angles of the interruptions in the contact surface.
  8. 8. A speed signal generator as claimed in any of claims 3 to 7 in which the number of rotating rolling elements does not correspond to a multiple of the number of the residual contact surfaces and/or the number of the interruptions in the contact surface.
  9. 9. A speed signal generator as claimed in any of claims 3 to 8 when appendant to claim 2 in which the interruptions in the contact surface are provided on a rotating axially displaceable adjusting flange having the bellshaped contact surface thereon.
  10. 10. A speed signal generator as claimed in claim 9, in which a drive shaft is coupled to a driven shaft by the adjusting flange and the two shafts are angularly adjustable relative to one another upon axial displacement of the adjusting flange.
  11. I 1. A speed signal generator as claimed in claim 10. in which helical splines for effecting relative angular adjustment of the shafts upon axial displacement of the adjusting flange are arranged such that the adjusting flange is displaced towards the rolling elemens by the drive torque of the drive shaft.
  12. 12. A speed signal generator as claimed in any of claims 2 to 1 1. in which the angle of slope of the bell-shaped contact surface is smaller than or no greater than the effective angle of friction of the rolling elements thereon.
  13. 13. A speed signal generator as claimed in any of claims 1 to 12 in which each rolling element is held in a radial direction by at least one spring opposing the centrifugal force.
  14. 14. A speed signal generator as claimed in claim 13, in which at least one compression spring absorbing the centrifugal force is provided between the outer end of each guide pin and the respective rolling element.
  15. 15. A speed signal generator as claimed in claim 14, in which each compression spring is arranged between sliding washers.
  16. 16. A speed signal generator as claimed in any of claims 1 to 15, in which the guide pins of the guide spider are secured to a rotatable ring which is displaceably guided in an axial direction.
  17. 17. A speed signal generator as claimed in any of claims 1 to 16, in which the rolling elements are disc-like roller rings and have a bearing bore for receiving the respective guide pin.
  18. 18. A speed signal generator constructed and arranged and adapted to operate substantially as hereinbefore particularly described with reference to and as illustrated in the accompanying drawings.
GB2148178A 1978-02-03 1978-05-23 Speed signal generators particularly for injection timers Expired GB1595837A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19782804580 DE2804580A1 (en) 1978-02-03 1978-02-03 SPEED MEASURING SECTION, ESPECIALLY FOR INJECTION TIME ADJUSTER

Publications (1)

Publication Number Publication Date
GB1595837A true GB1595837A (en) 1981-08-19

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB2148178A Expired GB1595837A (en) 1978-02-03 1978-05-23 Speed signal generators particularly for injection timers

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DE (1) DE2804580A1 (en)
GB (1) GB1595837A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2285301A (en) * 1993-12-27 1995-07-05 Giat Ind Sa A mechanically-controlled adjustable-phase torque-transmitting coupling for a weapon
GB2510364A (en) * 2013-01-31 2014-08-06 Jaguar Land Rover Ltd A device for effecting an axial shift of a rotary shaft for use in a variable camshaft drive mechanism

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4895119A (en) * 1988-05-16 1990-01-23 Briggs & Stratton Corporation Speed governing apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2285301A (en) * 1993-12-27 1995-07-05 Giat Ind Sa A mechanically-controlled adjustable-phase torque-transmitting coupling for a weapon
US5535661A (en) * 1993-12-27 1996-07-16 Giat Industries Mechanically controlled torque transmission mechanism and weapon including such a mechanism
GB2285301B (en) * 1993-12-27 1998-06-03 Giat Ind Sa Mechanically controlled adjustable-phase torque transmitting coupling for a weapon
GB2510364A (en) * 2013-01-31 2014-08-06 Jaguar Land Rover Ltd A device for effecting an axial shift of a rotary shaft for use in a variable camshaft drive mechanism
US9476328B2 (en) 2013-01-31 2016-10-25 Jaguar Land Rover Limited Device for effecting an axial shift of a rotary shaft for use in a variable camshaft drive mechanism
GB2510364B (en) * 2013-01-31 2017-08-30 Jaguar Land Rover Ltd A device for effecting an axial shift of a rotary shaft for use in a variable camshaft drive mechanism

Also Published As

Publication number Publication date
DE2804580A1 (en) 1979-08-09

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PCNP Patent ceased through non-payment of renewal fee