Pre-tensioning tool for an engine tensioner

Patent metadata

Field	Value
Publication number	US-9643302-B2
Application number	US-201514876893-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 7, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A multi-axis tool for pre-tensioning a camshaft-drive element tensioner in an engine includes a housing having first and second faces and a length. The housing defines a first passage arranged along a first axis and a second passage arranged along a second axis. The second axis is parallel to the first axis and each passage extends through the length of the housing. The tool also includes a first lug arranged on and extending beyond the first face. The first passage extends through the first lug. The tool also includes a second lug extending beyond the second face and arranged along a third axis that is parallel to the first axis. An indicator rod is arranged partially within the second passage and configured to selectively extend beyond the first face. An elastic element is arranged inside the second passage and configured to extend the indicator rod beyond the first face.

First claim

The invention claimed is:

1. A multi-axis tool for pre-tensioning a camshaft-drive element tensioner in an internal combustion engine, the tool comprising:
a housing having a first face, a second face, and a length defining a span between the first and second faces, wherein the housing defines a first passage arranged along a first axis and a second passage arranged along a second axis, and wherein the second axis is parallel to the first axis and each of the first and second passages extends through the length of the housing;
a first lug arranged on and extending beyond the first face, wherein the first passage extends through the first lug;
a second lug arranged on and extending beyond the second face and arranged along a third axis that is parallel to the first axis;
an indicator rod arranged partially within the second passage and configured to selectively extend beyond the first face; and
an elastic element arranged inside the second passage and configured to extend the indicator rod beyond the first face.

2. The multi-axis tool according to claim 1 , wherein:
the elastic element is a coil spring;
the indicator rod includes a ledge; and
the coil spring is configured to seat against the ledge and preload the indicator rod toward the first face.

3. The multi-axis tool according to claim 2 , further comprising a plate fixed to the housing at the second face and configured to retain the coil spring inside the second passage.

4. The multi-axis tool according to claim 1 , wherein the tensioner includes a tensioner body and a rotatable arm, and wherein the second lug is configured to engage the rotatable arm of the tensioner.

5. The multi-axis tool according to claim 4 , wherein:
the tensioner includes a first indicator feature arranged on the tensioner body and a second indicator feature arranged on the rotatable arm;
a relative position of the first and second indicator features is configured to indicate a tensioning state of the tensioner; and
the indicator rod is configured to engage and align the first and second indicator features when extended beyond the first face by the spring to engage both indicator features.

6. The multi-axis tool according to claim 1 , wherein the tensioner includes a fastener configured to fix the tensioner in position on the engine, and wherein the first passage provides operative access to the fastener.

7. The multi-axis tool according to claim 6 , wherein the fastener includes a fastener head, and wherein the housing defines a cavity aligned with the first passage and configured to provide clearance for the fastener head.

8. The multi-axis tool according to claim 1 , wherein the first lug includes an external hex shape configured to be engaged by a complementary hex socket for rotating the housing and the second lug about the first axis.

9. The multi-axis tool according to claim 1 , wherein the indicator rod includes a handle section extending beyond the second face, and wherein the handle section is configured to facilitate retraction of the indicator rod into the second passage by compressing the elastic element.

10. The multi-axis tool according to claim 1 , wherein the engine includes a timing cover defining an access opening for the multi-axis tool, and wherein the housing is configured to fit into the access opening and engage the tensioner via the second lug.

11. A method of pre-tensioning a camshaft-drive element tensioner, the method comprising:
providing an internal combustion engine having a camshaft, and a camshaft-drive element;
pre-starting a fastener to operatively connect the camshaft-drive element tensioner to the engine, wherein the tensioner includes:
a tensioner body configured to contact the camshaft-drive element;
a rotatable arm configured to load the tensioner against the camshaft-drive element; and
a first indicator feature arranged on the tensioner body and a second indicator feature arranged on the rotatable arm, such that a relative position of the first and second indicator features is configured to indicate a tensioning state of the tensioner;

providing a multi-axis tool for engagement with the camshaft-drive element tensioner, wherein the multi-axis tool includes:
a housing having a first face, a second face, and a length defining a span between the first and second faces, wherein the housing defines a first passage arranged along a first axis and a second passage arranged along a second axis, and wherein the second axis is parallel to the first axis and each of the first and second passages extends through the length of the housing;
a first lug arranged on and extending beyond the first face, wherein the first passage extends through the first lug;
a second lug arranged on and extending beyond the second face and arranged along a third axis that is parallel to the first axis;
an indicator rod arranged partially within the second passage and configured to selectively extend beyond the first face; and
an elastic element arranged inside the second passage and configured to extend the indicator rod beyond the first face;

engaging the second lug of the multi-axis tool with the rotatable arm of the tensioner;
rotating the housing via the first lug such that the second lug is rotated about the first axis and thereby rotates the rotatable arm;
aligning the first and second indicator features via the indicator rod being extended beyond the first face by the elastic element; and
fixing the tensioner in position on the engine by tightening the fastener to specification torque.

12. The method according to claim 11 , wherein:
the elastic element is a coil spring;
the indicator rod includes a ledge; and
said engaging and aligning the first and second indicator features includes seating the coil spring against the ledge and preloading the indicator rod toward the first face.

13. The method according to claim 12 , further comprising a plate fixed to the housing at the second face, and wherein said preloading the indicator rod toward the first face includes retaining the coil spring inside the second passage via the plate.

14. The method according to claim 11 , wherein:
the tensioner includes a first indicator feature arranged on the tensioner body and a second indicator feature arranged on the rotatable arm; and
said aligning the first and second indicator features via the indicator rod includes extending the indicator rod through and engaging both the first and second indicator features.

15. The method according to claim 11 , wherein:
the tensioner includes a fastener configured to fix the tensioner in position on the engine;
the first passage provides operative access to the fastener; and
said tightening the fastener to specification torque includes accessing the fastener through the first passage.

16. The method according to claim 11 , wherein:
the fastener includes a fastener head;
the housing defines a cavity aligned with the first passage and configured to provide clearance for the fastener head; and
said engaging the second lug of the multi-axis tool with the rotatable arm of the tensioner includes aligning the clearance in the housing with the fastener head.

17. The method according to claim 11 , wherein the first lug includes an external hex shape and the multi-axis tool includes a complementary hex socket, and wherein said rotating the housing via the first lug includes engaging the external hex shape with the hex socket.

18. The method according to claim 11 , wherein the indicator rod includes a handle section extending beyond the second face, f

Assignees

• Gm Global Tech Operations Llc

Inventors

• Staley Eric D
• Stabinsky Mark
• Tow Patrick J

Classifications

• F16H7/08

  Means for varying tension of belts, ropes or chains  (pulleys of adjustable construction F16H55/52) · CPC title

• B25B25/00 Primary

  Implements for fastening, connecting or tensioning of wire or strip · CPC title

• B25B27/0035

  for motor-vehicles (wrenches for mounting or dismounting wheels B60B29/003) · CPC title

• F16H7/12 Primary

  of an idle pulley · CPC title

• F16H7/24

  Equipment for mounting belts, ropes, or chains · CPC title